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Gas for 78 Avanti II

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  • Gas for 78 Avanti II

    Good news, I took my leaking gas tank for my 78 Avanti to a radiator shop and they said they can repair the leak. I had to go to two shops to get one willing to do it. The options were $60 to fix the leak or $300 to coat the inside.
    My question is, can the 350 Corvette engine in my 78 Avanti use unleaded gas?

    1978 Avanti II

  • #2
    That should be no problem as the cars of that vintage were designed for unleaded fuel.

    Denny L


    • #3
      The bigger question probably is: "will it run on Regular 87 Oct. without pinging?" Probably NOT.
      Second Generation Stude Driver,
      Proud '54 Starliner Owner


      • #4
        I have seen 78's run on 87 octane with no problems.


        • #5
          Never a problem with my 79.
          Originally posted by Green53 View Post
          I have seen 78's run on 87 octane with no problems.
          Lou Van Anne
          62 Champ
          64 R2 GT Hawk
          79 Avanti II


          • #6
            The 'vette engines by 1978 had been detuned to the point they might even run on peanut oil. So regular should be just fine. The mighty SBC of that era was from 175 - 220 HP with 8.2 -8.9 CR. I won't dig far enough into the specs to look at valve size but I'll bet you have the better set of heads for the era.

            Get the car running and on the road then lets talk upgrades as I know you've spent all you want to currently. When you can free up a few hundred $$ talk to Comp Cams/Lunati and get that retarded OEM cam out of there and put in a good grind recommended by the aforementioned folks.

            If you have the 8.9 compression SBC in good shape, you'll be amazed at the difference you will see.