<PAGE>

                                                                       Ex. 10.48

            SIXTH AMENDMENT TO SECOND AMENDED AND RESTATED INVENTORY
              LOAN AND SECURITY AGREEMENT AND MODIFICATION OF NOTES

         THIS SIXTH AMENDMENT TO SECOND AMENDED AND RESTATED INVENTORY LOAN AND
SECURITY AGREEMENT ("SIXTH AMENDMENT") dated March 5, 2004 (the "EFFECTIVE
DATE"), is made by and between SILVERLEAF RESORTS, INC., a Texas corporation
f/k/a SILVERLEAF VACATION CLUB, INC., f/k/a ASCENSION CAPITAL CORPORATION,
successor by merger to ASCENSION RESORTS, LTD. d/b/a SILVERLEAF RESORTS, LTD., a
Texas limited partnership ("BORROWER"), whose address is 1221 Riverbend, Suite
120, Dallas, Texas 75247, and Heller Financial, Inc., a Delaware corporation
whose address is 500 West Monroe Street, Chicago, Illinois 60661 ("LENDER").

                                    RECITALS:

         A.       On December 27, 1995 Borrower and Lender entered into that
certain Loan and Security Agreement (the "ORIGINAL INVENTORY LOAN AGREEMENT") as
amended on February 28, 1996 and December 27, 1996 (the "ORIGINAL INVENTORY
LOAN"); and

         B.       The Original Inventory Loan as amended was modified and
amended pursuant to that certain Amended and Restated Inventory Loan and
Security Agreement (the "INVENTORY LOAN AGREEMENT") between Borrower and Lender
dated September 1, 1999 (the "INVENTORY LOAN"); and

         C.       The Inventory Loan was modified and amended pursuant to that
certain Second Amended and Restated Inventory Loan and Security Agreement (the
"SUPPLEMENTAL LOAN AGREEMENT") between Borrower and Lender dated March 1, 2001
to provide for a Supplemental Loan in the amount of $10,000,000.00 (the
"SUPPLEMENTAL LOAN"), to be advanced to Borrower through a Supplemental
Revolving Period ending on March 23, 2001 (the "ORIGINAL SUPPLEMENTAL REVOLVING
PERIOD"), as modified and amended by that certain First Amendment to Second
Amended and Restated Inventory Loan and Security Agreement between Borrower and
Lender dated March 15, 2001 (the "FIRST AMENDMENT TO SUPPLEMENTAL LOAN"), and
that certain letter agreement dated April 12, 2001 ("LETTER AGREEMENT") (the
Original Inventory Loan Agreement, the Inventory Loan Agreement, the
Supplemental Loan Agreement; and all amendments and modifications thereto are
collectively referred to as the "LOAN AGREEMENT"); and

         D.       The Supplemental Loan Agreement, as amended, was further
modified by that certain Second Amendment to Second Amended and Restated
Inventory Loan and Security Agreement between Borrower and Lender dated May 3,
2001 (the "SECOND AMENDMENT TO SUPPLEMENTAL LOAN") to extend to Borrower a
secured working capital credit facility (the "WORKING CAPITAL FACILITY") which
is a component of the Supplemental Loan Agreement and provides for advances to
be additionally secured pursuant to the terms in the Second Amendment to
Supplemental Loan; and

         E.       The Supplemental Loan Agreement, as amended, was further
modified by that certain Third Amendment to Second Amended and Restated
Inventory Loan and Security

<PAGE>

Agreement between Borrower and Lender effective July 27, 2001 (the "THIRD
AMENDMENT TO SUPPLEMENTAL LOAN") to provide for certain terms in respect of
interest payments under the Working Capital Facility; and

         F.       The Supplemental Loan Agreement, as amended, was further
modified by that certain Fourth Amendment to Second Amended and Restated
Inventory Loan and Security Agreement between Borrower and Lender dated April
30, 2002 (the "FOURTH AMENDMENT TO SUPPLEMENTAL LOAN") extending the
Availability Period, the Revolving Period, the Supplemental Availability Period,
the Supplemental Revolving Period, and the maturity dates for the Inventory Loan
and the Supplemental Loan; and

         G.       The Supplemental Loan Agreement, as amended, was subsequently
amended by that certain Fifth Amendment to Second Amended and Restated Inventory
Loan and Security Agreement between Borrower and Lender dated November 21, 2003
(the "FIFTH AMENDMENT TO SUPPLEMENTAL LOAN") to, among other things, modify the
manner in which Eligible Note Receivables may be replaced, expand the
eligibility requirements for Eligible Unsold Timeshare Intervals and amend
certain financial covenants; and

         H.       Pursuant to the terms of the Fourth Amendment to Supplemental
Loan, Borrower executed and delivered to Lender (i) that certain Second Amended
and Restated Promissory Note (Supplemental Loan) dated April 30, 2002 (the
"SECOND AMENDED AND RESTATED PROMISSORY NOTE (SUPPLEMENTAL LOAN)"), and (ii)
that certain Amended and Restated Revolving Promissory Note (Inventory Loan)
dated April 30, 2002 (the "AMENDED AND RESTATED REVOLVING PROMISSORY NOTE
(INVENTORY LOAN)"); and

         I.       Lender and Other Lenders are entering into that certain Second
Amended and Restated Intercreditor Agreement dated of even date herewith (the
"SECOND INTERCREDITOR AGREEMENT"); and

         J.       Borrower, Lender and Union Bank of California, N.A. are
entering into the Fourth Amendment to Amended and Restated Receivables Loan and
Security Agreement dated of even date herewith ("FOURTH AMENDMENT TO AMENDED AND
RESTATED RECEIVABLES LOAN AGREEMENT"); and

         K.       The parties desire to further amend the terms of the Loan
Agreement, as amended, as set forth herein.

         NOW, THEREFORE, in consideration of the premises and the agreements,
provisions and covenants herein contained, Borrower and Lender agree as follows:

         1.       Recitals. The above recitals are true and correct and are
incorporated herein.

         2.       Incorporation. The Exhibits and Schedules attached hereto are
incorporated herein and made a part hereof.

         3.       Definitions All capitalized terms not defined herein shall
have the meanings ascribed to them in the Loan Agreement.

                                       2
<PAGE>

         4.       Loans; Modification Fee.

                  (a)      Borrower acknowledges, agrees and confirms that as of
the date hereof and after giving effect to the payments required in connection
herewith, the outstanding principal balances of the Supplemental Loan and the
Receivables Loan are, respectively, $8,343,084.78 and $15,686,297.31.

                  (b)      In exchange for Lender's agreements hereunder and
under the Fourth Amendment to Amended and Restated Receivables Loan Agreement,
Borrower has agreed to pay Lender and Union Bank of California, N.A. a
modification fee more specifically described in the Fourth Amendment to Amended
and Restated Receivables Loan Agreement.

         5.       Loan Payoff. As further consideration for Lender's agreements
under this Sixth Amendment, Borrower agrees to pay to Lender the entire
outstanding principal balance of the Inventory Loan pursuant to a payoff letter
to be delivered by Lender ("INVENTORY LOAN PAYOFF AMOUNT"). Such Inventory Loan
Payoff Amount shall be paid on or before the Effective Date by wire transfer
pursuant to transfer instructions provided by Lender. Upon receipt of the
Inventory Loan Payoff Amount and the satisfaction of the other conditions
contained in this Sixth Amendment, Lender will deliver to Borrower satisfactions
of mortgages associated with the Real Estate Collateral and any other lien
releases necessary to release Lender's lien on the Inventory and collateral
pledged to Lender as security for the Inventory Loan.

         6.       Release of Lender's Security Interest in Additional
Collateral. Lender hereby releases any and all security interest that Lender may
have in the Additional Collateral, the Ineligible Note Portfolio, the Additional
Resort Collateral, the Second Priority Collateral, the Eligible Unsold Timeshare
Intervals, the Real Estate Collateral and any other Shared Collateral which has
not been pledged to Lender as the Primary Lender. Except as modified herein,
Lender shall retain its lien with respect to the Collateral encumbered pursuant
to Section 2.2 of the Supplemental Loan Agreement.

         7.       Profitable Operations. The Profitable Operations financial
covenant set forth in Section 10(f)(v) of the Fourth Amendment to Supplemental
Loan is hereby amended and restated as follows:

         Borrower will not permit Consolidated Net Income to be less than $1.00
         for (A) any fiscal year, commencing with the fiscal year ending
         December 31, 2002, and (B) any two consecutive fiscal quarters (which
         quarters shall be measured on an individual rather than a cumulative
         basis). Notwithstanding anything stated to the contrary herein, the
         Allowance Increase (as defined in the Fifth Amendment to Supplemental
         Loan) shall not be taken into consideration in performing the
         calculation of Consolidated Net Income; provided, however, the
         Allowance Increase shall apply only to the Allowance Increase that
         occurred during the quarter ending on March 31, 2003. Any further
         increases to the allowance for uncollectible notes shall be included
         for purposes of calculating Consolidated Net Income.

         8.       Limitation on Other Debt; Modifications to Other Debt
Instruments. Section 6.4(a) restricting the Borrower's ability to obtain
additional financing and Section 6.4(c)

                                       3
<PAGE>

requiring Lender's consent to any modification to the Textron Documents, DZ
Documents, Bond Holder Exchange Documents, Sovereign Documents and Other Debt
Instruments are hereby deleted and the word Omitted is substituted therefor. It
shall no longer be an Event of Default for Borrower to incur any additional debt
or to enter into any modification, amendment, extension or termination of any of
the Textron Documents, the Sovereign Documents, DZ Documents, Bond Holder
Exchange Documents or any documents evidencing any other indebtedness of
Borrower.

         9.       Compensation of Senior Management. Section 6.4(b) is hereby
amended and restated as follows:

         The compensation of the senior management of the Borrower, as a group,
         is subject to the following limitations:

                  (a)      Base salary increases may not exceed twenty-five
percent (25%) each fiscal year; and

                  (b)      Incentive bonuses may not exceed twenty percent (20%)
of pre-tax net profits in each fiscal year.

         The modifications set forth in this paragraph 9 shall not be effective
until each of Textron and Sovereign modify the respective Textron Documents and
Sovereign Documents in a similar manner with respect to the compensation of
Senior Management.

         10.      Default or Termination of Assignments of Mortgage. Section
13(m) of the Fourth Amendment to Supplemental Loan is hereby deleted and the
word Omitted is substituted therefor.

         11.      Consent to Senior Subordinated Note Exchange. Borrower has
requested Lender's consent to Borrower's exchange of up to $28,467,000 (but not
less than $18,978,000) of 6% senior subordinated notes due in 2007 for an equal
amount of 8% senior subordinated notes due in 2010 (the "SENIOR SUBORDINATED
NOTE EXCHANGE"). Lender hereby consents to the Senior Subordinated Note
Exchange.

         The consent set forth in this paragraph 11 shall not be effective until
each of Textron and Sovereign provide written consent to the Senior Subordinated
Note Exchange.

         12.      Business Operations. The additional Event of Default set forth
in Section 15(g) of the Second Amendment to Supplemental Loan is hereby deleted.
Lender hereby waives any rights it may have with respect to enforcing Borrower's
compliance with the Business Plan or exercising any other right or remedy with
respect to the Business Plan.

         13.      Standby Manager. Lender hereby waives any rights it may have
to (i) replace any existing manager or to terminate any existing management
agreement to which Borrower is a party, (ii) exercise control over the removal
or appointment of a Standby Manager or the modification, termination or
replacement of the Standby Management Agreement, or (iii) exercise any other
right or remedy with respect to the Standby Manager or the Standby Management
Agreement. Furthermore, it shall no longer be an Event of Default for Borrower
to

                                       4
<PAGE>

enter into any modification, amendment, extension or termination of the Standby
Management Agreement.

         14.      Second Intercreditor Agreement. This Sixth Amendment is
conditioned upon the execution of the Second Intercreditor Agreement in the form
attached hereto as EXHIBIT A by Lender, Sovereign and Textron. Failure by either
Textron or Sovereign to enter into the Second Intercreditor Agreement shall
render this Sixth Amendment null and void.

         15.      Conditions Precedent; Closing.

                  (a)      Approval of Documents Prior to Closing Date. Borrower
has delivered to Lender (with copies to Lender's counsel), prior to the Closing
Date, and Lender has reviewed and approved in its sole discretion, prior to the
Closing Date, the form and content of all of the items specified in Subsections
(i) through (iv) below (the "SUBMISSIONS").

                  Lender shall have the right to review and approve any changes
to the form of any of the Submissions. If Lender disapproves of any changes to
any of the Submissions, Lender shall have the right to require Borrower either
to cure or correct the defect objected to by Lender. Under no circumstances
shall Lender's failure to approve or disapprove a change to any of the
Submissions be deemed to be an approval of such Submissions. All of the
Submissions were and shall be prepared at Borrower's sole cost and expense.
Borrower acknowledges that Lender will not enter into this Sixth Amendment
unless all of the following conditions precedent are satisfied by the Closing
Date.

                           (i)      A certificate in the form attached as
EXHIBIT B to be dated as of the Closing Date and signed by the president, vice
president, or secretary of Borrower;

                           (ii)     Copies of any amendments to the articles of
incorporation/charter and bylaws of Borrower not previously delivered to Lender,
certified to be true, correct and complete by Borrower and the Secretary of
State of the State of Texas and current certificates of good standing for
Borrower for the State of Texas and states where the Resorts are located, a
current certificate of authority to conduct business by the Secretary of State
in each state in which Borrower conducts business;

                           (iii)    A certificate of the Secretary of Borrower
certifying the adoption by the Board of Directors of Borrower of a resolution
authorizing Borrower to enter into and execute this Sixth Amendment and all such
documents requested by Lender in the form attached hereto as EXHIBIT C; and

                           (iv)     A certificate of the secretary or assistant
secretary of Borrower certifying the incumbency, and verifying the authenticity
of the signatures, of the specified officers of Borrower authorized to sign this
Sixth Amendment and all such documents requested by Lender in the form attached
hereto as EXHIBIT D.

                  (b)      Execution And Delivery of Loan Documents. Borrower
shall have delivered to Lender, on or before the Closing Date, the following
Loan Documents, each of which shall be in the form of the respective Loan
Documents attached hereto as Exhibits:

                                       5
<PAGE>

                           (i)      Closing Opinions of Counsels for Borrower
(EXHIBIT E).

                           (ii)     Textron, and Sovereign shall have executed
and delivered to Lender, on or before the Closing Date, the Second Intercreditor
Agreement, in the form attached hereto as EXHIBIT A.

                           (iii)    Such other agreements, documents,
instruments, certificates and materials as Lender may request to evidence the
Indebtedness, to evidence and perfect the rights and Liens and security
interests of Lender contemplated by the Loan Documents, and to effectuate the
transactions contemplated herein.

                  (c)      Fourth Amendment to Amended and Restated Receivables
Loan Agreement. Borrower and Lender shall have executed, on or before the
Closing Date, the Fourth Amendment to Amended and Restated Receivables Loan
Agreement, in the form attached hereto as EXHIBIT F.

         16.      Borrower Confirmation. Borrower hereby ratifies and confirms
that the Loan Agreement and other Loan Documents as amended herein are in full
force and effect and agrees that as modified, the Loan Agreement and the other
Loan Documents are and continue to be in full force and effect and enforceable
in accordance with their respective terms. Borrower hereby incorporates by
reference all covenants, warranties, and representations contained in the Loan
Documents and reaffirms such covenants, warranties, and representations as of
the day hereof.

         17.      Borrower Estoppel; Lender's Waiver. Execution of this Sixth
Amendment by Lender shall be without prejudice to Lender's rights at any time in
the future to exercise any and all rights conferred upon it by any of the Loan
Documents in accordance with their original terms as previously and hereby
amended. Except as expressly provided in this Sixth Amendment and the Second
Intercreditor Agreement, neither the Sixth Amendment nor any provision hereof or
of any other documents given in connection herewith shall constitute or shall be
construed to constitute a waiver of any default, right, or remedy of Lender
under the Loan Documents subsequent to the date hereof. Any failure by Lender at
any point in time during the term of the Second Amended and Restated Promissory
Note (Supplemental Loan), the Loan Documents or the Supplemental Loan Agreement
to insist upon strict and timely compliance with the terms and provisions of
each such document shall not be deemed a waiver either expressly or implied by
Lender of any or its rights under any such document nor shall the same excuse
Borrower's obligation to strictly and timely perform its obligation hereunder
and therein.

         18.      Release. Borrower hereby desires to fully comprise, release
and settle any and all claims, counterclaims, liabilities, damages, defenses,
demands and causes of action that Borrower has or may have against Lender
related to or that may have arisen, may arise or are or become assertable as a
result of events occurring in connection with the Lending Relationship (as
defined below), including any claims, causes of action or defenses based on the
negligence of Lenders or on any "lender liability" theories of, among others,
bad faith, unfair dealings, duress, coercion, control, misrepresentation,
omission, misconduct, overreaching, unconscionability, disparate bargaining
position, reliance, equity subordination, fraud, failure of consideration in
whole or in part, or otherwise, and do hereby intend to release, compromise and
settle all such claims and matters, whether known or unknown, whether reduced to
judgment, liquidated or

                                       6
<PAGE>

unliquidated, fixed, contingent, matured, unmatured, disputed, undisputed,
legal, equitable, secured or unsecured and whether they arose collaterally,
directly, derivatively, or otherwise between the Borrower on the one hand, and
Lender, on the other hand (collectively, the "RELEASED CLAIMS"). Borrower hereby
stipulates, agrees, covenants, warrants and represents unto the Lender that
Borrower does not have any outstanding claims, counterclaims, liabilities,
damages, defenses, demands or causes of action against Lender or its successors,
assigns, directors, officers, employees, agents and/or attorneys. Borrower does
hereby unconditionally forever release, acquit, settle and discharge Lender and
its successors, assigns, directors, officers, employees, agents and attorneys of
and from the Released Claims and Borrower hereby declares the Released Claims
forever released, acquitted, settled and discharged. As used herein, the term
"Lending Relationship" shall mean a collective reference to the Loan Agreement,
any other Loan Documents, together with any and all negotiations, discussions,
acts, omissions, renewals, extensions, collateral documents, loan agreements,
term sheets and other agreements and actions related thereto.

         19.      Complete Agreement, Etc. There are and were no oral or written
representations, warranties, understandings, stipulations, agreements, or
promises made by either party or by any agent, employee or other representative
of either party pertaining to the subject matter of the Sixth Amendment which
have not been incorporated into the Sixth Amendment, except as set forth in the
Second Intercreditor Agreement. The Sixth Amendment shall not be modified,
changed, terminated, amended, superseded, waived or extended except by a written
instrument executed by the parties hereto. If any term comment or condition of
this Sixth Amendment is held to be invalid, illegal, or unenforceable as to a
particular person, entity, or situation, the Sixth Amendment will be enforced to
the fullest extent permitted by law as to any other person, entity, or
situation. Except as specifically modified by the terms of the Sixth Amendment
and the Second Intercreditor Agreement, the Second Amended and Restated
Promissory Note (Supplemental Loan) and all the remaining Loan Documents shall
not be affected by the Sixth Amendment and each shall remain in full force and
effect. Except for paragraph 6 above, nothing herein contained shall be
construed to impair Lender's security under any of the Loan Agreements or Loan
Documents nor to limit or impair any rights or powers that Lender now enjoys or
may hereafter enjoy under the Loan Documents for recovery of the Indebtedness
secured hereby.

         20.      Further Assurances. Borrower agrees to execute such further
documents, instruments and agreements as Lender may require from time to time to
effectuate the terms and conditions and understandings of this Sixth Amendment.

         21.      Borrower Representations. Borrower hereby represents and
warrants to the Lender that:

                  (a)      The Persons executing the Sixth Amendment on behalf
of the Borrower have full authority to execute the Sixth Amendment on behalf of
Borrower and to bind Borrower thereby;

                  (b)      The execution and delivery by Borrower of the Sixth
Amendment and the performance thereunder by Borrower has not and will not result
in a breach of or constitute a default under any mortgage, lease, bank loan,
credit arrangement or other instrument or

                                       7
<PAGE>

agreement to which either Borrower or the Collateral securing the Loans may be
bound or affected;

                  (c)      Borrower is a corporation duly formed, validly
existing and in good standing under the laws of the State of Texas;

                  (d)      The execution, delivery and performance by the
Borrower of the Sixth Amendment and other Loan Documents as amended as of the
date hereof, have been duly and validly authorized and all consents and
approvals which are necessary for authorization, binding affect, performance,
and enforceability of the Sixth Amendment and all other Loan Documents have been
received; and

                  (e)      Borrower will not be, on or after the date hereof, a
party to any contract or agreement which prohibits Borrower's execution of the
Sixth Amendment or the Fourth Amendment to Amended and Restated Receivables Loan
Agreement, or compliance with the terms of the Loan Agreement, the Loan
Documents or the Receivables Loan Agreement. Except as set forth in the Fourth
Amendment to Amended and Restated Revolving Credit Agreement dated of even date
herewith, by and among Borrower, Sovereign and Liberty Bank, Borrower has not
agreed or consent to cause or permit in the future (upon the happening of a
contingency or otherwise) any of the Collateral, whether now owned or hereafter
acquired, to be subject to a Lien except in favor of Lender as provided herein.

                  (f)      Except as disclosed on the attached Schedule 25,
there are no actions, suits, proceedings, orders or injunctions pending or, to
the best of Borrower's knowledge, threatened against or affecting Borrower any
Resort or the Intervals, at law or in equity, or before or by any governmental
authority, in any case individually in which the claim exceeds or would
reasonably be expected to exceed $50,000 or all cases for which claims in the
aggregate exceed or could reasonably be expected to exceed $250,000. Borrower
has received no notice from any court or governmental authority alleging that
Borrower has violated any applicable timeshare act, any of the rules or
regulations thereunder, or any other applicable laws.

                  (g)      Except as otherwise disclosed by the Borrower to
Lender in writing, since September 30, 2003, there has occurred no materially
adverse change in the financial condition or business of the Borrower and its
subsidiaries as shown on or reflected in the consolidated balance sheet of the
Borrower and its subsidiaries as of September 30, 2003, or the consolidated
statement of income as of such date, other than changes in the ordinary course
of business that have not had any materially adverse effect either individually
or in the aggregate on the business or financial condition of the Borrower or
any of its subsidiaries. Since September 30, 2003, the Borrower has not made any
Distribution.

         22.      Counterparts. This Sixth Amendment may be executed in any
number of counterparts, each of which shall be deemed an original and all of
which shall together constitute one and the same instrument

         23.      Fair Consideration. Lender's agreements contained herein
constitute valuable, adequate and fair consideration for the obligations of the
Borrower hereunder.

                                       8
<PAGE>

         24.      No Lender Control. Lender has never been, nor will it ever be,
a partner, joint venturer, alter ego, manager, or controlling person of the
Borrower.

         25.      No Other Representation. Borrower acknowledges and agrees that
neither Lender nor any person or entity acting on its behalf has made any
representation or promise to Borrower which is not expressly set forth herein or
in the other Loan Documents.

            [THE REMAINDER OF THIS PAGE IS LEFT INTENTIONALLY BLANK]

                                       9
<PAGE>

         IN WITNESS WHEREOF, Borrower and Lender have caused this Sixth
Amendment to be executed and delivered by their duly authorized officers
effective as of the date first above written.

                                             BORROWER:

                                             SILVERLEAF RESORTS, INC., a Texas
                                             corporation

                                             By: /S/ HARRY J. WHITE, JR.
                                                 -------------------------------
                                             Name: Harry J. White, Jr.
                                             Its: CFO

                                             LENDER:

                                             HELLER FINANCIAL, INC.

                                             By: /S/ MARTIN HERLMANN
                                                 -------------------------------
                                             Name: Martin Herlmann
                                                   Its: AVP

Exhibits and Schedules to Agreement:

<TABLE>
<S>            <C>
Exhibit A      Second Intercreditor Agreement
Exhibit B      Certificate of Borrower
Exhibit C      Certificate of Resolutions of Borrower
Exhibit D      Incumbency Certificate
Exhibit E      Closing Opinions of Counsel of Borrower
Exhibit F      Fourth Amendment to Amended and Restated Receivables Loan Agreement
Schedule 25    Litigation Schedule
</TABLE>