OK, glad to help if I can. I'm also considering bringing a junk block to demonstrate the preliminary work to convert to the same size main bearings front to rear on stovebolt engines. That involves boring all the main bearing holes to the same diameter, and installing reducer sleeves to fit small block 400 main bearings. Then the downsized bearing bores are line-bored and the crankshaft is reground to SBC 400 main bearing diameter. That procedure also saves a "worn out" crankshaft.
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!