Also, why whittle that long, twisty crankshaft all the way down to SBC bearing diameter?
The OD of the SBC 400 main bearing is only about .030" smaller than the OD of the front main bearing on a stovebolt, so if one wants a set of mains that are the same diameter front to rear, that's the logical choice. I'll probably bore the front hole in the block a little bigger and custom machine a spacer for that one. A narrower main bearing shell will cut down on rotating friction, while still giving the crank plenty of support. Making the #2 and #3 main caps from billet steel with four bolts instead of 2 bolt cast iron caps will also stabilize the crank and make the block stiffer to minimize the flex on both items.
Jerry
