There is a very simple modification of the 1954 / 1955 235 block that will allow the use of later model, more available main bearings. It's also possible to modify the block and crankshaft to use mains for a small block 400 Chevy V8, which are inexpensive and plentiful.
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!