The engines with the locator tabs at the parting line don't use main bearing shims- - - - -only the ones with dowels top and bottom. NO insert bearing connecting rods are shimmed- - - -only Babbit bearing rods have them.
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!