My friends dad is real arrogant he thinks he's a know it all. Him and his mechanic buddy say you cant run a 350 Chevy SB bored .60 over and run it on pump gas. I know this is complete Bull**** cause my 73 camaro ran on 93 pump gas beautifully for a year with a .60 over 350SB. IT was a 2 bolt main 350 chevy sb bored .60 over with a comp cam,heavy duty eagle crank, Stock 64cc cast iron heads, .60 Keith black piston heads, roller rockers, edelbrock performer RPM intake manifold and a 650 CFM street avenger carb also hooker super comp exhaust headers were jus some of the mods i had on it The block then took a crap on me because the #4 cylinder wall had a created a "pin hole". Regardless I jus wanna know how do I explain to this guy that you can run a 60 over block on 93 pumpgas. I just cant figure out how to word it. I got some Chevy Highperformance Articles on this that im gonna show him too but I really wanna make him look like a dumbass lol. Any info will help thanks!

 

They're confused. The amount of over-bore has little if anything to do with running on pump gas. The compression ratio of the engine or more importantly the dynamic compression ratio will determine if you can run on pump gas.

There are issues with longevity and (sometimes) cooling with a large overbore however.

Jody

 

Your friend's Dad just showed how little he actually knows. That's funny. As Jody pointed out, the DCR determines the minimum octane.