Originally Posted by
korey
Most of the marinas in the area and a few land based filling stations near our larger lakes (Cumberland and Dale Hollow in KY/TN) are carrying the Rec-90 (ethanol-free, 90 octane unleaded gasoline blend designed for use in recreational/marine engines). I've never believed in running any special gas in an old 10:1 compression ratio big block, but my boat LOVES this rec-90... Maybe it me subliminally justifying paying $3.89/gal on the water, but I swear the boat runs better on it!
Unless you changed pistons, your 454 has around 8.5:1 CR, same as mine. It will run on damn near anything lol. And no, your not crazy, All of my carburated engines run better on Non-ethanol fuel. I think the lack of Ethanol is what you notice more than the higher octane.
1988 Supra Sun Sport 454 PCM
1972 Olds Cutlass 455
1998 BMW 750il
1996 BMW M3 coupe
1995 Toyota Tacoma 4x4