Just recently I tore down the 350 to check it all out. The block is a1969 vintage two bolt and the heads are the same era. I was expecting the machinist to tell me I had a crack in either the block or heads. To my surprise it all checked out good. (It’s seen 260* more than once)
The engineer's in the late 60’s really got it right when they designed the Chevy 350 small block.
By the way this engine has not been babied, I run it upwards of 7000 rpm every time and shoot it with 150 shot of NOS. The only thing that is not genuine GM is the pistons and camshaft.
Sorry for my radio silence the last few months.... haven't had a ton of time to work on the old 68 burb until recently. Last week I finally got some painting done on the undercarriage after all the body work we did in Feb. The 68 is officially 100% rust free! What a victory!!! Now on to the fun stuff that will turn people's heads when they see it, i.e. New rims, tinted windows, removing oxidation and adding a clear coat to give it that patina look, etc., are all on the horizon this year.