[Will]

BracketRacer, I hope you're right. The mains are oversized by .001" according to most of the references I have, maybe only by .0005" if we use the 3.4385 +/- .0005". The thing is, when we measured the mains the block was cold, it had been sitting in the back of my blazer for two days and it's getting down below freezing here at night.

I'll be taking it back on Friday and talking to the shop about it. My machinist just got another Chevy Big Block from them and it was dead-on right in the middle of the tolerance, which is the way he says every other block he's gotten has been. Just my luck to get the one block they screw up on.

1/2" - your idea about the paint isn't too far from my last-resort approach. One of the things my machinist showed me is pure copper sheets in .001" thicknesses. He said we could shim the bearings with this stuff if it came down to it as a last resort. I wouldn't think pure copper would hurt heat transfer characteristics in any way, it's a better conductor of heat than cast iron.