Gentlemen, Before you all jump in, the obvious suppliers do not have these on the shelf. I need .040" UNDER on the mains, and .010 UNDER on the big end. If anyone has the mains, or know who might have them, let me know. History: My rebuilt 206 engine snapped a dry sump pump key, leading to instant oil loss. This happened just a hundred yards from chequer. I had the engine and car stopped quickly, but damage was done. The worst part was the essentially new crank was destroyed (cracked), a non-trivial expense to replace along with all the other bits that got partially roasted.
I have not experienced 40 under anything.....ever. Maybe exists for big diesels or industrial motors but that will be a hard find. I have experience with and complete faith in properly welded up cranks. I have one in my own 328 to get the stroke I wanted. Id get it welded.