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             AMENDMENT NO. 1 TO STOCK AND ASSET PURCHASE AGREEMENT,
                          DATED AS OF NOVEMBER 21, 1995


                  This  Amendment  No. 1 to Stock and Asset  Purchase  Agreement
dated as of November 21, 1995 (this  "Amendment No. 1") is made and entered into
as of the 11th day of December 1995, by and among Castle Energy  Corporation,  a
Delaware  corporation  ("Castle"),  Indian  Refining I Limited  Partnership,  an
Illinois limited partnership  ("IRLP"),  Indian Refining & Marketing I, Inc., an
Illinois  corporation  and the sole general  partner of IRLP ("IRMI")  (IRMI and
IRLP are collectively referred to as the "Asset Sellers"),  and American Western
Refining, Inc., a Delaware limited partnership ("Buyer").

                  WHEREAS,  Castle,  the Asset  Sellers and Am West GP, Inc. the
general  partner  of the Buyer,  are  parties  to that  certain  Stock and Asset
Purchase Agreement dated as of November 21, 1995 (the "Purchase Agreement").

                  WHEREAS,  Am West GP, Inc., has assigned all of its rights and
obligations under the Purchase Agreement to Buyer.

                  WHEREAS, the parties desire to amend the Purchase Agreement as
set forth in this Amendment No. 1.

                  NOW, THEREFORE, in consideration of the foregoing premises and
the mutual  covenants  and  agreements  set forth  herein,  and  intending to be
legally bound, Castle, the Asset Sellers and Buyer hereby agree as follows:

                  1. The following  definition is hereby added in Section 1.1 of
the Purchase Agreement,  immediately preceding the definition of "Asset Purchase
Price":

                           "Amendment  No. 1" shall mean  Amendment No. 1 to the
                  Stock and Asset  Purchase  Agreement  dated as of November 21,
                  1995 among Castle, the Asset Sellers and Am West GP, Inc.

                  2. The definition of "Outstanding Liens" in Section 1.1 of the
Purchase Agreement is hereby amended to read in its entirety as follows:

                           "Outstanding  Liens" shall mean the Liens  identified
                  on  Schedule  1.1B  attached  to the  Purchase  Agreement,  as
                  amended by Amendment No. 1."

                  3. The  definition  of  "Schedule  1.1B" in Section 1.1 of the
Purchase Agreement is hereby amended to read in its entirety as follows:

                           "Schedule   1.1B"  shall  mean  the  schedule   dated
                  November  21,  1995 and  attached  to the  Purchase  Agreement
                  (before giving effect to Amendment No. 1), as  supplemented by
                  the schedule  dated December 8, 1995 and attached to Amendment
                  No.  1 as  Exhibit  A to  Amendment  No.  1,  which  schedules
                  collectively  identify all Persons known to have a Lien on any
                  of the Purchased Assets at December 8, 1995, and in each case,
                  the amount of such Liability.

                  4. The  parties  hereto  hereby  agree that the Seller Note is
hereby  amended to read in its  entirety as set forth on Exhibit B to  Amendment
No. 1.


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                  5. The list of Excluded  Contracts  set forth on Schedule 2.2D
to the  Purchase  Agreement  is hereby  amended  by adding the  following  as an
"Excluded Contract": that certain Agreement made March 23, 1994 between IRLP and
ABB Lummus  Crest Inc. for License and Basic  Engineering  Relating to a Delayed
Coker  Plant,  Lawrenceville  Refinery,  Illinois.  Schedule  4.4 is  amended by
deleting the reference to such Contract.

                  6. Section 7.11(b) of the Purchase Agreement is hereby deleted
in its entirety and replaced by the following  Section  7.11(b),  reading in its
entirety as follows:

                  "(b) If,  at any time,  Buyer  shall  elect to pay any  amount
secured by any one of the Outstanding Liens, the amount so paid shall reduce the
obligations of the Buyer under the Seller Note dollar for dollar.  The foregoing
is also permitted by the second sentence of Section 2(c) of the Seller Note."

                  7. The Purchase Agreement, as amended by this Amendment No. 1,
remains in full force and effect.

                  8. This  Amendment No. 1 shall be governed by and construed in
accordance  with the laws of the State of New York,  without regard to its rules
on conflicts of law.

                  9.  This  Amendment  No.  1 may be  executed  in  two or  more
counterparts,  all of which shall be considered one and the same agreement,  and
shall become a binding  agreement when one or more counterparts have been signed
by each of the parties and delivered to each of the other parties.

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                  IN WITNESS  WHEREOF,  the  parties  hereto  have  caused  this
Amendment No. 1 to be duly executed as of the date and year first above written.

                                      CASTLE ENERGY CORPORATION


                                     By: /s/ RICHARD E. STAEDTLER
                                         -------------------------------
                                         Title: Chief Financial Officer


                                     INDIAN REFINING I LIMITED PARTNERSHIP

                                     By:  Indian Refining & Marketing I
                                                Inc., General Partner


                                              By: /s/ CHRIS A. WOODS
                                                 --------------------------
                                                 Title: Vice President





                                     INDIAN REFINING & MARKETING I INC.


                                     By: /s/ CHRIS A. WOODS
                                         -------------------------------
                                         Title: Vice President




                                     AMERICAN WESTERN REFINING, L.P.



                                      By:  Am West GP, Inc., its general partner

                                              By: /s/ B.N. BANERJEE
                                                 --------------------------
                                                 Title: President



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