Need some input on my 86 SS. Wanting to get a 355 flat top piston short block and install the OEM intake and heads on it. I'm on a tight budget here! Has anyone used or heard of this combination? The guy at the engine company said it would not run on pump gas due the the CC's of the heads developing high compression. Not sure if he was just speaking of 87 octane or not.

 

If you're using the stock 58cc 305 heads it will probably bring it to needing 92 octane fuel. IMO anything in 10.5 to 1 compression you would need it , I'm personally at 10.3 to 1 compression and have no problems with detonation with 92 octane .Good luck