SUPPLY AGREEMENT

     This Agreement made as of the 29th day of April, 1996, by and between Ambac
International Corporation ("Ambac"), a Delaware corporation having its principal
place  of  business  at I-77 at  Killian  Road,  Columbia,  South  Carolina  and
Electronic  Fuel  Control,  Inc.  ("EFC"),  a  Georgia  corporation  having  its
principal  place of business at Suite 210,  4851 Georgia  Highway,  Forest Park,
Georgia.

     WHEREAS, Ambac has developed and sold dual fuel control systems for various
engine applications as set forth in Attachment A;

     WHEREAS,  EFC has developed  gaseous fuel technology and mixing devices for
use in the conversion  system under which naturally  aspirated and turbo charged
internal  combustion  engines can be fueled with compressed or liquefied natural
gas or propane, or converted to the use of multiple fuels; and

     WHEREAS, EFC has approached Ambac to develop a duel fuel control system for
use with the EFC gaseous fuel technology mixing device in a dual fuel conversion
system.

1.   DEFINITIONS

     For the purposes of this  Agreement,  the following  terms shall have these
     respective meanings:

     EFC Dual Fuel Control Systems and Components"  shall mean an electronically
     controlled,  closed loop, speed and load sensitive,  controller system, and
     components   thereof,   meant  to  control   both  diesel  and  gas  fuels,
     proportionately  metering both fuels via electronic control and said system
     shall be specifically developed for and adapted to a EFC Gaseous Fuel


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     Technology Mixing Device(s) as such term is defined below.

     "EFC Gaseous Fuel Technology  Mixing Device" shall mean the  electronically
     controlled,  closed loop natural  gas/diesel  conversion  system  initially
     developed by Frank Davis.

     "Ambac Products" shall mean the products sold hereunder.

     "Dual Fuel Control  Systems and  Components"  shall mean an Ambac developed
     electronic controller system, and components thereof, meant to control both
     diesel and gas fuels,  proportionately  metering both fuels via  electronic
     control,  and  which is not  developed  specifically  for EFC and for which
     Ambac  did not  use  Proprietary  Information,  as  such  term  is  defined
     hereunder, of EFC in the development thereof.

2.   DEVELOPMENT

     Ambac agrees to design and develop an EFC Dual Fuel Control  System(s)  and
     Components  for use with the EFC Gaseous Fuel  Technology  Mixing  Devices.
     Ambac  shall  immediately  begin  development  of an  analog  EFC Dual Fuel
     Control System and upon mutual  agreement of the parties,  it will commence
     development  of a  digital  EFC  Dual  Fuel  Control  System.  Ambac  shall
     establish proprietary part numbers in the name of EFC for the EFC Dual Fuel
     Control System(s) and Components.


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3.   EXCLUSIVE SALES RIGHTS

     A. Ambac agrees to sell EFC Dual Control Systems and Components only to EFC
     for a period of twenty  (20)  years from the date  hereof  and all  parties
     requesting   information  from  Ambac  on  EFC  Dual  Control  Systems  and
     Components and EFC Gaseous Fuel Technology  Mixing Device shall be referred
     by Ambac to EFC.

     B. After successful  completion of development and testing of the first EFC
     Dual Fuel Control Systems and Components required  hereunder,  agreement on
     price(s)  and the  exhaustion  of existing EFC supplies of its current dual
     fuel control systems  (including  EFC's existing  inventory of and its open
     orders for its current dual fuel control  systems),  EFC agrees to purchase
     from Ambac,  its  requirements  for dual fuel  control  systems for its EFC
     Gaseous Fuel Technology  Mixing Device(s) for a period of twenty (20) years
     from the  date  hereof  and upon the  terms  set  forth  herein;  provided,
     however,  that the technology  and price for  components  will allow EFC to
     remain  competitive  and  that  Ambac  is able  to  satisfy  EFC's  product
     requirement as requested on a timely basis and that the products  purchased
     hereunder  conform  to  industry  quality   standards.   If  Ambac  becomes
     non-competitive   hereunder,   it  shall  have  an  opportunity   meet  the
     competitive conditions.

     C. Ambac  shall  retain  the right to sell Dual Fuel  Control  Systems  and
     Components to any party; provided, however, Ambac shall be prohibited


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     from selling to any party other than EFC,  any Dual Fuel Control  System(s)
     developed  by Ambac  which are  identical  or  similar to the EFC Dual Fuel
     Control System(s) to be developed hereunder.

4.   SALES TERMS

     A. On or prior to the  completion of development of the respective EFC Dual
     Fuel Control  Systems and  Components,  the parties shall mutually agree on
     price terms for each component  thereof.

     B. All purchase  orders  placed by EFC with Ambac for Ambac  Products  sold
     hereunder  shall be subject in all respects to the terms and  conditions of
     this  Agreement,  including the Ambac's  Standard  Terms and  Conditions of
     Sale,  attached  hereto as Exhibit A and such terms and  conditions of this
     Agreement shall apply in lieu of any terms and conditions on EFC's purchase
     order forms or other related documents.

     C. EFC shall make payment for the Ambac Products purchased pursuant to this
     Agreement  in  accord  with the  terms as set  forth  in  EFC's  Terms  and
     Conditions  which are  attached  hereto as Exhibit B. Ambac  shall have the
     right to  change  the  Terms and  Conditions  set forth in  Exhibit A and B
     hereto, applicable to all unaccepted orders upon 120 days written notice to
     EFC.

     D. EFC will not return any of the Ambac  Products  purchased  hereunder for
     credit or exchange  unless and until EFC receives  Ambac's  consent.  Ambac
     shall not unduly withhold consent for the return of components  supplied by
     Ambac that are subject to coverage under the Ambac Warranty, as such


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     term is  defined  below,  due to a  defect  attributable  to  Ambac  or its
     vendors,  which consent will not be unreasonably  withhold and the decision
     rendered by Ambac in each case shall be in accordance with industry custom,
     standards and practice.

5.   WARRANTY

     Ambac Products sold under this  Agreement  shall be subject to Ambac's then
     current standard warranty  provisions covering the Ambac Products which are
     contained in Ambac's Warranty Administration Manual ("Ambac Warranty"). Any
     changes from  Ambac's  standard  warranty  policy must be agreed to by both
     parties in writing.

6.   OWNERSHIP OF TECHNOLOGY

     Ambac shall  retain all  technological  rights to the EFC Dual Fuel Control
     Systems and Components and EFC shall retain all technological rights to the
     EFC Gaseous Fuel Technology Mixing Device(s);  provided,  however, that the
     technology  to the EFC Dual Fuel  Control  Systems  and  Components  is not
     covered under the existing patents owned by the Davis Family Trust.

7.   CONFIDENTIALITY

     In  connection  with  the  performance  of this  Agreement,  Ambac  and EFC
     contemplate  the possible  disclosure  to each other of portions of certain
     "Proprietary Information" (defined below) of the disclosing party.


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     A. For the purpose of this Agreement,  the term  "Proprietary  Information"
     shall  mean  any and  all  technical  information  bearing  an  appropriate
     confidentiality  notice which is originated or collected by the  disclosing
     party,  whether recorded in documentary form or otherwise,  relating to the
     design,  construction,  operation,  manufacture,  testing, servicing and/or
     selling  EFC Dual Fuel  Control  Systems and EFC  Gaseous  Fuel  Technology
     Mixing   Devices   including   without    limitation,    design   concepts,
     specifications,  drawings,  manufacturing  procedures,  parts  lists,  test
     procedures  and  data,  bill of  materials,  performance  data,  names  and
     addresses of components suppliers and service and maintenance manuals.

     B. The receiving party agrees that it will maintain Proprietary Information
     received  from the other party hereto in strict  confidence  using the same
     standard of care it uses in protecting its own Proprietary  Information and
     it will not disclose to any third party such Proprietary Information unless
     and until it is released from this obligation in writing by the other party
     hereto.  The receiving party may disclose  Proprietary  Information only to
     its  employees  necessarily  in the use thereof for the  purposes set forth
     herein.  The  receiving  party  agrees  to  advise  such  employees  of the
     confidential nature of the Proprietary Information and of the existence and
     importance of this Agreement and the terms  protecting the  confidentiality
     of Proprietary Information.


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     C. The receiving  party will not use such  Proprietary  Information for any
     purpose other than those set forth herein.

     D. The  obligations  of this  Agreement  shall not apply to any part of the
     Proprietary  Information which the receiving party can show to have been in
     the public domain or in the receiving party's possession at the time of the
     disclosure hereunder.

8.   TERM AND TERMINATION

     A. This Agreement shall continue in force and effect for a period of twenty
     (20) years  from the date  hereof,  unless it is  otherwise  terminated  by
     either party for "good cause",  which shall include,  but not be limited to
     any  material  or  repetitive  breach  by either  party of any  obligation,
     policy, procedure or requirement set forth in this Agreement, if such party
     shall fail to correct such breach within forty-five (45) days after receipt
     of written notice, which notice shall specify the grounds for such breach.

     B. In the case of a  termination,  the  terminating  party shall give sixty
     (60) days prior  written  notice of  termination  to the other  party.  The
     forty-five  (45) day  period  provided  above to allow for cure of a breach
     shall,  for purposes of calculating  the sixty (60) days notice period,  be
     included as part of such sixty (60) day period.

     C. Within thirty (30) days after the  effective  date of  termination,  EFC
     shall pay all monies due and owing hereunder. EFC shall pay interest on any
     past due balances at the rate of fifteen percent (15%) per annum and


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     shall  also pay the  Company's  cost of  collection,  including  reasonable
     attorney fees. 9. NOTICES

     All notices or communications  are permitted to be sent by one party to the
     other under the provisions of this Agreement  shall be in writing and shall
     be deemed sufficiently sent if transmitted by registered or certified mail,
     return receipt requested, postage prepaid, addressed as follows:

     If to Ambac:      Ambac International Corporation
                       P.O. Box 85
                       Columbia, SC 29202
                       Attention: President

     If to EFC:        Electronic Fuel Control, Inc.
                       Suite 210
                       4851 Georgia Highway 85
                       Forest Park, GA 30050
                       Attention: Frank Davis & J. R. Harper

10.  ASSIGNMENT

     This  Agreement is not assignable by either party without the other party's
     prior written  consent,  which consent will not be  unreasonably  withheld;
     provided,  however,  either party may assign this  Agreement to a successor
     entity  acquiring  all or  substantially  all of the  property,  assets and
     business of either party.

11.  WAIVER

     That the failure by either  party to enforce any term or  condition of this
     Agreement  shall not  constitute a waiver of that party's  right to enforce
     the same term or condition  upon the  occasion of a  subsequent  default or
     breach.


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12.  SEVERABILITY

     If one or more  provisions of this  Agreement  shall be held, by a court or
     other adjudicatory  body, to be unenforceable for any reason,  such finding
     shall in no manner affect the enforceability of the remaining provisions of
     this Agreement.

13.  CHOICE OF LAW

     This Agreement  shall be construed and enforced in accordance with the laws
     of the  State of  Georgia,  U.S.A.;  without  regard to the  principles  of
     conflict of laws thereof.

14.  RESOLUTION OF DISPUTES

     In the event of any  dispute or  difference  arising  out of or relating to
     this  Agreement  or the breach  thereof,  the parties  shall use their best
     efforts to settle such disputes or differences.  To this effect, they shall
     consult and negotiate with each other, in good faith and  understanding  of
     their mutual interest,  to reach a just and equitable solution satisfactory
     to both parties.  If the parties do not reach such solution within a period
     of thirty (30) days,  then the  disputes or  differences  shall  finally be
     settled  and  determined  by a single  arbitrator  under  the then  current
     Commercial  Arbitration  Rules  of  the  American  Arbitration  Association
     ("AAA").  The arbitration shall be held and the award shall be deemed to be
     made in Augusta, Georgia. The decision and award of the arbitrator shall be
     final and judgment may be entered upon it in accordance with the applicable
     law in any court having jurisdiction.


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15.  FORCE MAJEURE

     Neither  party  shall be liable for  failure  to  perform  any part of this
     Agreement when such failure is due to strikes,  riots, fires, wars, acts of
     God,  or any other  contingencies  beyond  the  reasonable  control  of the
     parties.

16.  AMENDMENT

     This   Agreement  may  not  be  modified  or  terminated   orally,   an  no
     modification,  termination,  or attempted  waiver shall be valid unless set
     forth in writing signed by all of the parties hereto.

17.  BINDING AGREEMENT

     That this Agreement  shall be binding and conclusive  upon and inure to the
     benefit of the respective  parties hereto and their respective  successors,
     heirs, assigns, executors, administrators and legal representatives.

18.  ENTIRE AGREEMENT

     A. That this Agreement together with the Exhibits hereto are a part of this
     Agreement as though set forth in full herein.

     B. That this  Agreement  together  with the Exhibits  hereto,  contains the
     entire agreement of the parties hereto,  and this Agreement  supersedes any
     and terminates all previous agreements made between the parties hereto.

19.  EFFECTIVE DATE

     This  Agreement  shall commence as of the date it is fully executed by both
     parties hereto.


<PAGE>


AMBAC INTERNATIONAL                                ELECTRONIC FUEL CONTROL, INC.
CORPORATION

       /s/ Laurence D. Hurwitz                          /s/ Robby E. Davis
       -----------------------                          ------------------
By:    Laurence D. Hurwitz                         By:  Robby E. Davis
its    General Counsel &                           its  President
       Assistant Secretary


<PAGE>



                                    Exhibit A

                      Standard Terms and Conditions of Sale

1.   PURCHASE ORDERS

The Buyer  agrees  that the  terms and  conditions  set  forth  herein  shall be
applicable to all quotations and purchase  orders  covering the sale of Seller's
products and services and shall  supersede all printed terms and  conditions set
forth in Purchase  Orders used by the Buyer,  Seller shall not be deemed to have
waived  these  terms and  conditions  of sale if it fails to object to terms and
conditions  appearing  in Buyer's  purchase  orders and  Buyer's  acceptance  of
products or  services  called for in said orders  shall  constitute  the Buyer's
acceptance of these terms and conditions of sale as the only terms applicable to
the purchase of such goods or services.

2.   PRICES

Prices  are  subject to  adjustment  in  accordance  with  provisions  contained
elsewhere herein. In addition to the stipulated purchase price of the goods, any
and all taxes (not  including  any income or excess  profits  taxes) that may be
imposed by any taxing authority,  arising from the sale, delivery, or use of the
goods and for which the Seller may be held responsible for collection or payment
either on its own behalf or on behalf of the  Buyer,  shall be paid by the Buyer
to Seller upon the Seller's demand.

3.   DELIVERY, TITLE AND RISK OF LOSS

All goods shall be delivered to the Buyer F.O.B. the Seller's factory.  Title to
and the risk of loss of or damage to all goods sold hereunder  shall remain with
the Seller until, and shall pass to the Buyer upon, delivery of the goods to the
Buyer or any agent of the Buyer, including a common carrier or warehouse.

4.   INSPECTION

If upon  receipt and  inspection  of goods by Buyer at  destination,  such goods
shall appear not to be in conformance with the Contract, the Buyer shall, within
thirty (30) days after the receipt  hereof,  notify the Seller of such condition
and afford  Seller a  reasonable  opportunity  to inspect the goods and make any
appropriate  adjustment or  replacement.  The remedies  afforded Buyer under the
Paragraph 7 hereof  entitled  "Warranty"  shall be exclusive for defective goods
discovered upon inspection but shall not be cut off by reason of Buyer's failure
to discover the defect in the goods within the inspection  period provided above
this paragraph.

5.   PAYMENT

Unless otherwise provided,  payment for goods purchased and delivered under this
Contract shall be made in U.S.  dollars at the prices  stipulated  within thirty
(30) days after the date of delivery to the F.O.B.  point. Buyer shall not delay
payment for goods pending inspection under Paragraph 4 above.

6.   PACKAGING

The goods to be delivered  hereunder  shall be packed and packaged in accordance
with sound commercial practice for domestic shipment. Unless otherwise provided,
export or other special packaging will be at additional charge to the Buyer.

7.   EXCUSABLE DELAYS

Buyer acknowledges that the goods called for hereunder are to be manufactured by
or for Seller to fulfill this order and that the delivery dates are based on the
assumption  that  there  will be no delay due to causes  beyond  the  reasonable
control of Seller.  Seller shall not be charged with any  liability for delay or
non-delivery  when due to delays of supplier,  acts of God or the public  enemy,
compliance in good faith with any  applicable  foreign or domestic  governmental
regulation or order whether or not it proves to be invalid,  fires, riots, labor
disputes,  unusually  severe  weather or any other cause  beyond the  reasonable
control of Seller.  To the extent that such causes actually retard deliveries on
the part of the Seller,  the time for the  performance  shall be extended for as
many days  beyond the date  thereof  as is  required  to obtain  removal of such
causes.  This provision shall not,  however,  relieve Seller from using its best
efforts to avoid or remove  such  causes.  This  provision  shall not,  however,
relieve  Seller  from using its best  efforts to avoid or remove such causes and
continue performance with reasonable dispatch whenever such causes are removed.

8.   LIMITATION ON LIABILITY

The price allocable in this Contract to any product or service alleged to be the
cause of any loss or damage  to the Buyer  shall be  ceiling  limit on  Seller's
liability,  whether founded in Contract or tort (including negligence),  arising
out of, or  resulting  from (i) this  Contract  or the  performance  of breached
thereof, (ii) the design,  manufacture,  deliver,  sale, repair,  replacement or
(iii) the use of any such product or the  furnishing of any such service.  In no
event  shall  Seller  have any  liability  of any  incidental  or  consequential
damages.

9.   COMPLIANCE WITH FAIR LABOR STANDARDS ACT

Seller  hereby  certifies  that  goods  sold  hereunder  which are  produced  or
manufactured in the United States are produced in compliance with the Fair Labor
Standards  Act of 1938,  as  amended.  All  requirements  as to the  certificate
contemplated  in the October 26, 1949 amendment shall be considered as satisfied
by the certification.

EXHIBIT A.EF


<PAGE>

                                    EXHIBIT B

                            EFC Terms and Conditions

TERMS:   2% Net 10th Proximo