Inliners International Forums General Discussion Engines 327 pistons in +.125 chevy 250

I've talked to Richard who has 4" pistons in a Pontiac engine. He said he has had a couple blocks he tried it in and failed on only a couple of them.

I have a standard bore pontiac 230 block that the thinnest part sonic checked at .238" (and a .030 over 250 block .060" thinner! Both engines use the same STD bore), so if the 230 was bored .125" over would still have .113" on the thinnest part, which was the front of cylinder #1 (on both blocks). Maybe Pontiac's had a few thick runs?

BTW, Richard has this 4" bore engine in a mid sixties El Camino and drives around Pahrump and Las Vegas. His cooling system didn't look fancy or excessive. IMO, tune and radiator size have much larger roles in cooling than cylinder wall thickness, especially when talking less than a tenth of an inch of metal difference.