<PAGE>

                                                                  Exhibit 10.175


                 INSTALLMENT SALE CONTRACT (SECURITY AGREEMENT)

PURCHASER(S):                         SELLER:
MEADOW VALLEY                         CATERPILLAR FINANCIAL SERVICES CORPORATION
CONTRACTORS, INC.                     2120 West End Avenue
4411 S. 40TH, SUITE D11               Nashville, TV  37203-0001
PHOENIX, AZ 85040
County: MARICOPA
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Subject to the terms and conditions set forth below and on the reverse side
hereof, Seller hereby sells the equipment described below (the "Unit" or
"Units") to Purchaser, and Purchaser (if more than one, jointly and severally),
having been offered both a cash sale price and a time sale price, hereby buys
the Units from Seller on a time sale basis.
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   NEW     (IF USED)                                                  DELIVERED
   OR      FIRST        MODEL    DESCRIPTION OF UNIT(S)    SERIAL#    CASH SALE
   USED    USED                                                           PRICE
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(1)USED                 980F     Caterpillar WHEEL LOADER  8JN00570   73,920.00




<TABLE>
<CAPTION>
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<S>       <C>                                  <C>                                         <C>
FIRST     DESCRIPTION OF ADDITIONAL SECURITY
USED      (MAKE, MODEL & SERIAL NUMBER)        Sub-Total.................................  $ 73,920.00
--------------------------------------------   Sales Tax.................................  $  3,696.00
                                               1. Total Cash Sale Price..................  $ 77,616.00
                                                  Cash Down Pay
--------------------------------------------      Net Trade-in Allow           0.00
FIRST     DESCRIPTION OF TRADE-IN EQUIPMENT    2. Total Down Payment.....................  $      0.00
USED      (MAKE, MODEL & SERIAL NUMBER)        3. Unpaid Balance of Cash Price (1-2).....  $ 77,616.00
--------------------------------------------   4. Official Fees (Specify)................  $    275.00
                                                  DOCUMENTATION FEE          275.00

                                               5. Physical Damage Insurance..............  $
--------------------------------------------   6. Principal Balance
                                                  (Amount Financed)(3+4+5)...............  $ 77,891.00
Trade-in Value                                 7. Finance Charge
Less Owing to (___n/a____)                        (Time Price Differential)..............  $  6,018.52
Net Trade-in Allowance                0.00     8. Time Balance
                                                  (Total of Payments)(6+7)...............  $ 83,909.52
Location of Units: 4411 S. 40TH STREET         9. Time Sale Balance
                   PHOENIX, AZ 85040 MARICOPA     (Deferred payment Price)(2+8)..........  $ 83,909.52
                                              10. Annual Percentage Rate                          7.90%
[ILLEGIBLE]                                   11. Date FINANCE CHARGE begins to accrue MARCH 10, 2002
</TABLE>

Purchaser hereby sells and conveys to Seller the above described Trade-in
Equipment and warrants it to be free and clear of all claims, liens, security
interests and encumbrances except to the extent shown above.

     1.   PAYMENT: Purchaser shall pay to Seller, at P.O. Box 730681, DALLAS TX
75373-0681 or such other location Seller designates in writing, the Time Balance
(Item 8 above) as follows [check(a) or (b)]:

[X] (a) in 24 equal monthly installments of $3,496.23 each, with the first
installment due on MARCH 10, 2002 and the balance of the installments due on the
like day of each month thereafter, (except no payments shall be due during the
month(s) of (__n/a__)), until the entire indebtedness has been paid; or

__  (b) in accordance with the Payment Schedule attached to this Contract.

(Provisions of section 1 continued on reverse.)
      SEE REVERSE SIDE FOR ADDITIONAL TERMS AND CONDITIONS WHICH ARE A PART
                                OF THIS CONTRACT.

LIABILITY INSURANCE COVERAGE FOR BODILY INJURY AND PROPERTY DAMAGE CAUSED TO
OTHERS IS NOT INCLUDED IN THIS CONTRACT.

NOTICE TO PURCHASER: (1) DO NOT SIGN THIS CONTRACT BEFORE YOU READ IT OR IF IT
CONTAINS ANY BLANK SPACES: (2) YOU ARE ENTITLED TO AN EXACT COPY OF THE CONTRACT
YOU SIGN: (3) UNDER THE LAW YOU MAY HAVE THE RIGHT TO PAY OFF IN ADVANCE THE
FULL AMOUNT DUE AND TO OBTAIN A PARTIAL REFUND OF THE FINANCE CHARGE.

PURCHASER ACKNOWLEDGES RECEIPT OF A FULLY COMPLETED COPY OF THIS CONTRACT
EXECUTED BY PURCHASER. THIS CONTRACT IS NOT BINDING UPON SELLER UNTIL EXECUTED
BY AN AUTHORIZED REPRESENTATIVE OF SELLER.

Purchaser(s) and Seller have duly executed this contract as of 3-10, 2002.

Purchaser(s)                          Seller:
MEADOW VALLEY                         CATERPILLAR FINANCIAL SERVICES CORPORATION
CONTRACTORS, INC.



By /s/ BRADLEY E. LARSON              By /s/ MAUREEN JOHNSON
   -------------------------------       ----------------------------------

Name (PRINT) Bradley E. Larson        Name (PRINT) Maureen Johnson
             ---------------------                 ------------------------

Title PRESIDENT/CEO                   Title Option Financing Representative
      ----------------------------          -------------------------------
<PAGE>

                         ADDITIONAL TERMS AND CONDITIONS

     1.   PAYMENT (continued): Purchaser shall pay to Seller a late payment
charge equal to the lesser of (a) the highest charge allowed by law or (b) 5% of
the amount of any payment (including any accelerated payment) not made when due
under this Contract (or such later date as may be required by applicable law).
Upon prepayment in full or acceleration of the total unpaid Time Balance,
Purchaser shall receive a rebate of the unearned portion of the Finance Charge
computed on an actuarial basis less a processing fee. Except as otherwise
expressly provided herein, the obligations of Purchaser hereunder shall not be
affected by any defect in, damage to, loss of or interference with possession or
use of any Unit, by the attachment of any lien or claim to any Unit or for any
to her cause.

     2.   DISCLAIMER OF WARRANTIES: Purchaser acknowledges and agrees that
Seller is not the manufacturer of the Unit(s) and that Purchaser has selected
each Unit based on Purchaser's own judgment without any reliance whatsoever on
any statement or representations made by Seller. AS BETWEEN SELLER AND
PURCHASER, THE UNIT(S) ARE PROVIDED "AS IS" WITHOUT ANY WARRANTIES OF ANY KIND.
SELLER HEREBY EXPRESSLY DISCLAIMS a) ALL WARRANTIES OF MERCHANTABILITY, b) ALL
WARRANTIES OF FITNESS FOR A PARTICULAR PURPOSE, AND c) ALL WARRANTIES AGAINST
INFRINGEMNET OR THE LIKE. Seller assigns to Purchaser its interest in any of the
manufacturer's warranties on the Unit(s).

     3.   POSSESSION, USE AND MAINTENANCE: Purchaser shall not(a) use any Unit
improperly, carelessly, unsafely or in violation of any law or regulation or for
personal, family, or household purposes or for any purpose other than in
Purchaser's business (including agricultural business); (b) permit the use of
any Unit by anyone other than Purchaser or change the permanent location of any
Unit from the county and state specified above without the prior written consent
of Seller; or (c) sell, lease, assign or transfer, or create or suffer to exist
any lien, claim, security interest or encumbrance on any of its rights hereunder
or in any Unit. The Units are and shall remain personal property irrespective of
their use or manner of attachment to realty. Upon prior notice to Purchaser,
Seller or its agent shall have the right (but not the obligation) at all
reasonable times to inspect any Unit. Purchaser shall at its expense maintain
the Units in good operating order, repair and condition. Purchaser shall not
alter any Unit or affix any equipment to any Unit if such alteration or addition
would impair the originally intended function or reduce the value of such Unit.
Any alteration or addition to any Unit shall be at the sole risk of Purchaser.

     4.   TAXES: Purchaser shall promptly pay all taxes, assessments, fees and
other charges when levied or assessed against any Unit or the ownership or use
thereof, or this Contract or any payments made or to be made to Seller.

     5.   WAIVER AND INDEMNITY: PURCHASER HEREBY AGREES TO RELEASE, DEFEND,
INDEMNIFY AND HOLD HARMLESS SELLER, ITS DIRECTORS, OFFICERS, EMPLOYEES, AGENTS
AND ASSIGNS FROM AND AGAINST ANY CLAIMS OF PURCHASER OR THIRD PARTIES, INCLUDING
CLAIMS BASED UPON BREACH OF CONTRACT, BREACH OF WARRANTY, PERSONAL INJURY,
PROPERTY DAMAGE, STRICT LIAIBLITY OR NEGLIGENCE, FOR ANY LOSS, DAMAGE OR INJURY
CAUSED BY OR RELATING TO THE DESIGN, MANUFACTURE, SELECTION, DELIVERY,
CONDITION, OPERATION, USE, OWNERSHIP, MAINTENANCE OR REPAIR OF ANY UNIT.
FURTHER, PURCHASER AGREES TO BE RESPONSIBLE FOR ALL COSTS AND EXPENSES INCLUDING
REASONABLE ATTORNEYS FEES, INCURRED BY SELLER OR ITS DIRECTORS, OFFICERS,
EMPLOYEES, AGENTS AND ASSIGNS IN DEFENDING SUCH CLAIMS OR IN ENFORCING THIS
PROVISION. UNDER NO CONDITION OR CAUSE OF ACTION SHALL SELLER BE LIABLE FOR ANY
LOSS OF ACTUAL OR ANTICIPATED BUSINESS OR PROFITS OR ANY SPECIAL, INDIRECT OR
CONSEQUENTIAL DAMAGES.

     6.   INSURANCE: Purchaser, at is expense, shall keep each Unit and all
equipment listed as Additional Security insured against all risks of their full
insurable value and shall maintain comprehensive public liability insurance in
an amount reasonably acceptable to Seller. All such insurance shall be in such
form and with such companies as Seller shall reasonably approve, shall be
primary, without right of contribution from any insurance carried by Seller, and
shall provide that such insurance may not be cancelled or altered so as to
affect the interest of Seller without at least 30 days' prior written notice to
Seller. All insurance covering loss or damage to the Units and Additional
Security shall name Seller (or its designee) as loss payee and be payable to
Seller as its interest may appear. Purchaser agrees to notify Seller of any
occurrence which may become the basis of an insurance claim hereunder and not to
make any adjustments with insurers without Seller's prior written consent. Prior
to the first delivery of any Unit to Purchaser, Purchaser shall deliver to
Seller satisfactory evidence of such insurance coverage.

     7.   EVENTS OF DEFAULT: Each of the following shall constitute an "Event of
Default" hereunder: (a) Purchaser shall fail to make any payment to Seller when
due hereunder or fail to observe or perform any other covenant, agreement or
warranty made by Purchaser hereunder; (b) any representation or warranty of
Purchaser contained herein or in any document furnished to Seller in connection
herewith shall be incorrect or misleading when made; (c) any Unit or additional
security shall become lost, stolen, destroyed, irreparably damaged or subject to
any sale, lien, claim, security interest or encumbrance (other than in favor of
Seller or is assignee); (d) any default shall occur under any other agreement
between Purchaser and Seller; (e) Purchaser or any guarantor of this Contract
shall cease to do business, become insolvent, make an assignment for the benefit
of creditors or file any petition under any bankruptcy, reorganization,
insolvency or moratorium law, or any other law for the relief of debtors; (f)
any involuntary petition shall be filed under any bankruptcy statute against
Purchaser or any guarantor of this Contract or any receiver, trustee, or similar
official shall be appointed to take possession of the properties of Purchaser or
any guarantor of this Contract unless such petition or appointment ceases to be
in effect within 30 days of said filing or appointment, (g) Seller shall
reasonably deem itself to be insecure; or (h) any breach or repudiation by any
guarantor shall occur under any guaranty obtained by Seller in connection with
this Contract.

     8.   REMEDIES: If any Event of Default shall occur, Seller may, at its
option, do any one or more of the following: (a) Declare all amounts due or to
become due under this Contract, excluding any unearned portion of the Finance
Charge, immediately due and payable; (b) recover any additional damages and
expenses sustained by Seller by reason of the breach of any covenant,
representation or warranty contained in this Contract; (c) enforce the security
interest granted hereunder; (d) without notice, liability or legal process,
enter upon the premises where any of the Units or additional security may be and
take possession thereof, and (e) require Purchaser to assemble the Units and
additional security and make them available to Seller at a place designated by
Seller which is reasonably convenient to both parties. Time is of the essence of
this Contract. Seller shall have all rights given to a secured party by law and
may retain all monies theretofore paid by Purchaser hereunder as compensation
for the reasonable use of the Units by Purchaser Seller may, at its option,
undertake commercially reasonable efforts to sell the Units and additional
security, and the proceeds of any such sale shall be applied: First, to
reimburse Seller for all reasonable expenses of retaking, holding, preparing for
sale, and selling the Units and additional security, including all taxes and
reasonable attorneys' fees, and second, to the extent not previously paid by
Purchaser, to pay Seller all amounts then due or accrued under this Contract,
including any accelerated payments and late payment charges. Any surplus shall
be paid to the person entitled thereto. Purchaser shall promptly pay any
deficiency to Seller. Purchaser acknowledges that sales for cash or on credit to
a wholesaler, retailer or user of the Units or additional security, and with or
without the Units or additional security being present at such sale, are all
commercially reasonable. Purchaser agrees to pay all reasonable attorneys' fees
(to the extent permitted by applicable law) and all costs and expenses incurred
by Seller in enforcing this Contract. The remedies provided herein shall be
cumulative and in addition to all other remedies at law or in equity. If
Purchaser fails to perform any of its obligations under this Contract, Seller
may (but need not) at any time thereafter perform such obligation, and the
expenses incurred in connection therewith shall be payable by Purchaser upon
demand.

     9.   SECURITY INTEREST; PURCHASER ASSURANCES AND REPRESENTATIONS: To secure
payment of Purchaser's indebtedness to Seller hereunder and the performance of
all obligations of Purchaser hereunder, Purchaser hereby grants to Seller a
continuing security interest in the Units, and in the equipment, if any,
described as Additional Security on the front of this Contract, including all
attachments, accessories and optional features for such Units and Additional
Security (whether or not installed thereon) and all substitutions, replacements,
additions and accessions thereto, and proceeds of all the foregoing including,
but not limited to, proceeds in the form of chattel paper. Purchaser will, at
its expense, do any act and execute, acknowledge, deliver, file, register and
record any document which Seller deems desirable in its discretion to protect
Seller's security interest and Seller's rights and benefits under this Contract.
Purchaser hereby irrevocably appoints Seller as Purchaser's Attorney-in-Fact for
the signing and filing of such documents and authorizes Seller to delegate these
limited powers. Purchaser represents and warrants to Seller that (a) Purchaser
has the power to make, deliver and perform under this Contract; (b) the person
executing and delivering this Contract is authorized to do so on behalf of
Purchaser; (c) this Contract constitutes a valid obligation of Purchaser,
legally binding upon it and enforceable in accordance with its terms; and (d)
all credit, financial and other information submitted to Seller in connection
with this Contract is and shall be true, correct and complete. Purchaser further
represents and warrants to Seller that Purchaser is and shall remain a
Corporation registered in the state of Nevada ("Business Location"); and
Purchaser will not change its form of business organization or Business Location
without prior written notice to Seller.

     10.  ASSIGNMENT; COUNTERPARTS: The rights and remedies of Seller under this
Contract may be assigned by Seller at any time. If this Contract is assigned by
Seller, the term "Seller" shall thenceforth mean Seller's assignee, and if
assigned to a partnership, shall thenceforth mean such partnership and, for
purposes of Sections 2, 4, 5 and 6, each partner in such partnership. If
notified by Seller, Purchaser shall make all payments due hereunder directly to
the party designated in such notice, without any offset or deduction whatsoever.
Purchaser waives, as to Seller's assignee, all claims and defenses Purchaser may
have or assert against Seller and agrees that no such claim or defense will be
asserted against Seller's assignee. No assignment of this Contract or any right
or obligation hereunder may be made by Purchaser without the prior written
consent of Seller. This Contract shall be binding upon and inure to the benefit
of Seller and Purchaser and their respective successors and assigns. Although
multiple counterparts of this document may be signed, only the counterpart
accepted, acknowledged and certified by Caterpillar Financial Services
Corporation on the signature page thereof as the original will constitute
original chattel paper.

     11.  EFFECT OF WAIVER; ENTIRE AGREEMENT; MODIFICATION OF CONTRACT; NOTICES:
No delay or omission to exercise any right or remedy accruing to Seller
hereunder shall impair any such right or remedy nor shall it be construed to be
a waiver of any breach or default of Purchaser. Any waiver or consent by Seller
under this Contract must be in writing specifically set forth. This Contract
completely states the rights of Seller and Purchaser with respect to the Units
and supersedes all prior agreements with respect thereto. No variation or
modification of this Contract shall be valid unless in writing. All notices
hereunder shall be in writing, addressed to each party at the address set forth
on the front of this Contract or at such other address as may hereafter be
furnished in writing.

     12.  SEVERABILITY; SURVIVAL OF COVENANTS: If any provision of this Contract
shall be invalid under any applicable law, such provision shall be deemed
omitted but the remaining provisions hereof shall be given effect. All
obligations of Purchaser under this Contract shall survive the expiration or
termination of this Contract to the extent required for their full observance
and performance.

     13.  APPLICABLE LAW, JURISIDICTION AND JURY TRIAL WAIVER PROVISIONS: This
Agreement shall be governed by and construed under the laws of the State of
Tennessee, without giving effect to the conflict-of-laws principles thereof, and
Purchaser hereby consents to the jurisdiction of any state of federal court
located within the State of Tennessee. THE PARTIES HERETO HEREBY WAIVE THE RIGHT
TO TRIAL BY JURY IN ANY ACTION ARISING OUT OF OR RELATED TO THIS AGREEMENT, THE
OBLIGATIONS OR THE COLLATERAL.