I modify the block to take smaller diameter main bearings (Small block Chevy 400 V8) and grind the crankshaft main bearing journals undersize to fit the bearings. All the mains end up the same diameter, and they're about 1/8" or more under the original diameter. That also solves the problem of scarce, ridiculously expensive main bearings. The stroker shafts I build end up with rod bearings way undersize from original, and a 4 5/16" stroke. That makes a 216 end up at 258 cubic inches, a 235 at 270, and a 261 almost 300, all running the same 235 pressure lubed crankshaft. The smaller diameter bearings reduce rotating friction dramatically.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!