<PAGE>
                                                                   EXHIBIT 10.51

                              AMENDED AND RESTATED
                                    GUARANTY


         THIS GUARANTY, is made this ______ day of June, by the undersigned,
whose address is 6200 Elmridge, Sterling Heights, Michigan 48310 (individually,
a "Guarantor" and collectively, the "Guarantors") , to and with Standard Federal
Bank, a federal savings bank ("Standard Federal")

RECITALS:

         A. McClain Group Leasing, Inc., a Michigan corporation ("Borrower"),
may from time to time request loans, advances or other financial accommodations
from Standard Federal and Standard Federal may, in its discretion, honor such
requests in whole or part and thereby Borrower may from time to time be indebted
to Standard Federal; and

         B. Standard Federal is unwilling to make loans, advances or extend
other financial accommodations to or otherwise do business with Borrower unless
the Guarantors unconditionally guaranty payment of all present and future
indebtedness and obligations of Borrower to Standard Federal; and

         C. Each of the Guarantors will directly benefit from Standard Federal's
making of loans advances or extending other financial accommodations to or
otherwise doing business with Borrower.

         NOW, THEREFORE, in order to induce Standard Federal to make loans,
advances or extend other financial accommodations to and otherwise do business
with Borrower and for other good and valuable consideration, the receipt and
sufficiency whereof are hereby acknowledged, Guarantors hereby covenant and
agree with Standard Federal as follows:

SECTION 1. GUARANTY

1.1 The Guarantors hereby irrevocably and unconditionally guaranty to Standard
Federal and its successors and assigns: (a) the full and prompt payment and
performance when due of the Indebtedness, as hereinafter defined; and (b) the
payment, compliance with and performance of all other obligations, covenants,
representations and warranties of every kind, nature and description in
accordance with all instruments and documents executed by the Borrower in favor
of Standard Federal, whether now owing or existing or heretofore or hereafter
created or arising, regardless of whether such obligations, covenants,
representations or warranties are held to be unenforceable, void or of no effect
against the Borrower and including without limitation, those under any loan
agreement and/or promissory note executed and delivered by Borrower to Standard
Federal, and any extensions, modifications or renewals thereof. The term
"Indebtedness" shall mean all principal, interest, attorneys' fees, commitment
fees, liabilities for costs and expenses and all other indebtedness, obligations
and liabilities under and in accordance with the terms of all instruments and
documents executed by Borrower in favor of Standard Federal, whether direct or
indirect, absolute or contingent and whether now owing or existing or heretofore
or hereafter created or arising, and regardless of whether such indebtedness,
obligations or liabilities are held to be unenforceable, void or of no effect
against the Borrower,


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and all costs, expenses and fees, including reasonable attorneys' fees, arising
in connection with the collection or enforcement of any or all amounts,
indebtedness, obligations and liabilities of Borrower to Standard Federal, as
described above, regardless of whether the Borrower is held to be liable for
such amounts. Each Guarantor acknowledges and agrees that any indebtedness of
the Borrower to Standard Federal as evidenced by any promissory note may be
extended or renewed upon maturity at the sole discretion of Standard Federal and
that the Indebtedness as defined herein, the payment of which is hereby
guaranteed, shall include, without limitation, all indebtedness and other
obligations as extended or renewed and as may be evidenced by any renewal
promissory note.

1.2 This is an irrevocable, unconditional and absolute guaranty of payment, and
not of collection, and the undersigned agrees that its liability on this
guaranty shall be immediate and Standard Federal may have immediate recourse
against the undersigned for full and immediate payment of the Indebtedness at
any time after the Indebtedness or any part thereof, has not been paid when due
(whether by acceleration or otherwise) or the Borrower has defaulted or
otherwise failed to perform when due any of its obligations, covenants,
representations or warranties to Standard Federal.

SECTION 2. LIABILITY OF GUARANTORS

2.1 The liability of Guarantors on this Guaranty shall not be contingent upon
the exercise or enforcement by Standard Federal of whatever remedies it may have
against the Borrower or others, or the enforcement of any lien or realization
upon any security or collateral Standard Federal may at any time possess. Any
one or more successive and/or concurrent actions may be brought hereon against
the Guarantors (or any of them) either in the same action, if any, brought
against Borrower or in separate actions, as often as Standard Federal, in it
sole discretion, may deem advisable. No election to proceed in one form of
action or proceeding, or against any party, or on any obligation, shall
constitute a waiver of Standard Federal's right to proceed in any other form of
action or proceeding or against other parties unless Standard Federal has
expressly waived such right in writing. Specifically, but without limiting the
generality of the foregoing, no action or proceeding by Standard Federal against
Borrower under any document or instrument evidencing or securing the
Indebtedness shall serve to diminish the liability of the Guarantors, except to
the extent Standard Federal realizes payment by such action or proceeding,
notwithstanding the affect of any such action or proceeding upon the Guarantors'
right of subrogation against Borrower. Receipt by Standard Federal of payment or
payments with knowledge of the breach of any provision with respect to any of
the Indebtedness shall not, as to the Guarantors, be deemed a waiver of such
breach. All rights, powers and remedies of Standard Federal hereunder and under
any other agreement now or at any time hereafter in force between Standard
Federal and the Guarantors shall be cumulative and not alternative and shall be
in addition to all rights, powers and remedies given to Standard Federal by law.

2.2 Each Guarantor agrees that its liability hereunder is absolute and
unconditional and that Standard Federal shall not be obligated (although it may
do so at its sole option) before being entitled to direct recourse against any
Guarantor to take any steps, whatsoever to preserve, protect, accept, perfect
Standard Federal's interest in, foreclose upon or realize on collateral
security, if any, for the payment of the Indebtedness or any other guaranty of
the Indebtedness or



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in any other respect exercise any diligence whatever in collecting or attempting
to collect the Indebtedness by any means.

2.3 The liability of the Guarantors shall in no way be affected or impaired by:
(a) any amendment, alteration, extension, renewal, waiver, indulgence or other
modification of the Indebtedness; (b) any settlement or compromise in connection
with the Indebtedness; (c) any subordination of payments under the Indebtedness
to any other debt or claim; (d) any substitution, exchange, release or other
disposition of all or any part of the Indebtedness; (e) any failure, delay,
neglect, act or omission by Standard Federal to act in connection with the
Indebtedness; (f) any advances for the purpose of performing any covenant of
agreement of the Borrower, or curing any breach; (g) the filing by or against
Borrower of bankruptcy, insolvency, reorganization or other debtor's relief
afforded Borrower pursuant to the present or future provisions of the Bankruptcy
Code or any other state or federal statute or by the decision of any court; or
(h) any other matter whether similar or dissimilar to the foregoing. The
obligations of the Guarantors are unconditional, notwithstanding any defect in
the genuineness, validity, regularity or enforceability of the Indebtedness or
any other circumstances whether or not referred to herein, which might otherwise
constitute a legal or equitable discharge or defense of a surety or guarantor.

2.4 Each of the Guarantors hereby waives each and every defense which, under
principles of guaranty or suretyship law or otherwise, would otherwise operate
to impair or diminish the liability of Guarantors hereunder, including, without
limitation: (a) notice of acceptance of this Guaranty and of creations of
Indebtedness of Borrower to Standard Federal; (b) any subrogation to the rights
of Standard Federal against Borrower until the Indebtedness has been paid in
full; (c) presentment and demand for payment of any Indebtedness of Borrower;
(d) protest, notice or protest, and notice of dishonor or default to the
Guarantors or to any other party with respect to any of the Indebtedness; (e)
all other notices to which the Guarantors might otherwise be entitled; (f) any
demand for payment under this Guaranty; (g) any defense arising by reason of any
disability or other defense of Borrower by reason of the cessation from any
cause whatsoever of the liability of the Borrower; (h) any rights to extension,
composition or otherwise under the Bankruptcy Code or any amendments thereof, or
under any state or other federal statute; and (i) any right or claim or claim of
right to cause a marshalling of Borrower's assets. No notice to or demand on the
Guarantors shall be deemed to be a waiver of the obligation of the Guarantors or
of the right of Standard Federal to take further action without notice or demand
as provided herein; nor in any event shall any modification or waiver of the
provisions of this Guaranty be effective unless in writing nor shall any such
waiver be applicable except in the specific instance for which given.

SECTION 3. WARRANTIES AND REPRESENTATIONS

3.1 Each Guarantor represents, warrants and covenants to Standard Federal that,
as of the date of this Guaranty: the fair salable value of such Guarantor's
assets exceeds its liabilities, including the liability undertaken pursuant to
this Guaranty; any financial statements of such Guarantor furnished Standard
Federal are true and correct and include in the footnotes thereto all contingent
liabilities of such Guarantor: there are not now pending any material court or
administrative proceedings or undischarged judgments against such Guarantor and
no federal or


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state tax liens have been filed or threatened against such Guarantor, nor is
such Guarantor in default or claimed default under any agreement for borrowed
money.

3.2 Each Guarantor agrees to immediately give Standard Federal written notice of
any material adverse change in its financial condition, including but not
limited to litigation commenced, tax liens filed, default claimed under its
indebtedness for borrowed money or bankruptcy proceedings commenced by or
against such Guarantor. Each Guarantor agrees to deliver, timely to Standard
Federal, annual financial statements for the preceding fiscal year; and at such
reasonable times as Standard Federal requests to furnish its current financial
statements to Standard Federal and permit Standard Federal or its
representatives to inspect at such Guarantor's offices, its financial records
and properties and make extracts therefrom in order to evaluate the financial
condition of such Guarantor. The Guarantors are fully aware of the financial
condition of the Borrower. The Guarantors deliver this Guaranty based solely
upon their own independent investigation and in no part upon any representation
or statement of Standard Federal with respect thereto. The Guarantors are in a
position to and hereby assume full responsibility for obtaining any additional
information concerning Borrower's financial condition as Guarantors may deem
material to its obligations hereunder; and Guarantors are not relying upon nor
expecting Standard Federal to furnish them any information in Standard Federal's
possession concerning Borrower's financial condition.

SECTION 4. MISCELLANEOUS

4.1 This Guaranty shall inure to the benefit of Standard Federal and its
successors and assigns, including each and every holder or owner of any of the
indebtedness guaranteed hereby. In the event that there shall be more than one
such holder or owner, this Guaranty shall be deemed a separate contract with
each such holder and owner. In the event that any person other than Standard
Federal shall become a holder or owner of any of the Indebtedness, each
reference to Standard Federal hereunder shall be construed as if it referred to
each such holder or owner.

4.2 This Guaranty shall be binding upon Guarantors and its successors and
assigns. Guarantors agree that recourse may be had against their earnings and
separate property for all of Guarantors' obligations under this Guaranty.

4.3 The liability of each Guarantor executing this Guaranty shall be joint and
several and the term "Guarantor" shall mean each and all such Guarantors.

4.4 This Guaranty and all rights and obligations hereunder, including matters of
construction, validity and performance, shall be governed by the laws of the
State of Michigan.

4.5 THIS GUARANTY IS FREELY AND VOLUNTARILY GIVEN TO STANDARD FEDERAL BY
GUARANTORS, JOINTLY AND SEVERALLY, WITHOUT ANY DURESS OR COERCION, AND AFTER
GUARANTORS, JOINTLY AND SEVERALLY, HAVE EITHER CONSULTED WITH COUNSEL OR BEEN
GIVEN AN OPPORTUNITY TO DO SO, AND GUARANTORS, JOINTLY AND SEVERALLY, HAVE
CAREFULLY AND COMPLETELY READ ALL OF THE TERMS AND PROVISIONS OF THIS GUARANTY.

4.6 This Guaranty amends and restates in its entirety the Guaranty dated July
17, 1996 by McClain Industries, Inc. in favor of Standard Federal.



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         IN WITNESS WHEREOF, this Guaranty was executed and delivered by the
undersigned on the day and year first above written.


                                        BORROWERS:

                                        MCCLAIN INDUSTRIES, INC., a Michigan
                                        corporation


                                        By:
----------------------------------          ------------------------------------
                                                 Mark S. Mikelait

                                                 Its:  Treasurer
                                                     ---------------------------

                                         38-1867649
                                        ----------------------------------------
                                        Taxpayer Identification Number

                                        MCCLAIN E-Z PACK INC., a Michigan
                                        corporation


                                        By:
----------------------------------          ------------------------------------
                                                 Mark S. Mikelait

                                                 Its:  Treasurer
                                                     ---------------------------

                                         38-3060202
                                        ----------------------------------------
                                        Taxpayer Identification Number




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<PAGE>


                                        MCCLAIN GALION, INC., a Michigan
                                        corporation


                                        By:
----------------------------------          ------------------------------------
                                                 Mark S. Mikelait

                                                 Its:  Treasurer
                                                     ---------------------------

                                         38-3060260
                                        ----------------------------------------
                                        Taxpayer Identification Number

                                        SHELBY STEEL PROCESSING COMPANY, a
                                        Michigan corporation


                                        By:
----------------------------------          ------------------------------------
                                                 Mark S. Mikelait

                                                 Its:  Treasurer
                                                     ---------------------------

                                         38-2205216
                                        ----------------------------------------
                                        Taxpayer Identification Number

                                        MCCLAIN TUBE COMPANY d/b/a QUALITY TUBE,
                                        a Michigan corporation


                                        By:
----------------------------------          ------------------------------------
                                                  Mark S. Mikelait

                                                  Its:  Treasurer
                                                      --------------------------

                                         38-3191647
                                        ----------------------------------------
                                        Taxpayer Identification Number

                                        MCCLAIN INTERNATIONAL FSC, a U.S. Virgin
                                        Islands corporation


                                        By:
----------------------------------          ------------------------------------
                                                  Kenneth D. McClain

                                                  Its:  President
                                                      --------------------------

                                        ----------------------------------------
                                        Taxpayer Identification Number



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                                        MCCLAIN SOUTHLAND CO, INC., a Florida
                                        corporation


                                        By:
----------------------------------          ------------------------------------
                                                  Mark S. Mikelait

                                                  Its:  Treasurer
                                                      --------------------------

                                         59-3241829
                                        ----------------------------------------
                                        Taxpayer Identification Number





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