I worked on a Chrysler 426 hemi once that would lock up the crankshaft every time the main bearing cap with the thrust flanges was torqued. If we removed the thrust-flanged bearing shell from the cap and replaced it with a non-flanged bearing, no problem. We found that the cap was bent, and tightening it eliminated all the end play on the crankshaft. The car the engine came from had been involved in a serious front end crash and the crankshaft had taken a hard lick on the vibration damper. The center of the cap would move back .015" as it was torqued down. A different thrust bearing cap and a line bore solved the problem.
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!