Here is the correct bearing set for the early model engines- - - - -with dowels on top and bottom. They also supposedly need the shim set. Sealed Power 960M, .010" undersize. Summit CLAIMS they're in stock. Given their habit of getting parts drop-shipped from the manufacturer, I have my doubts!

https://www.summitracing.com/parts/slp-960m10#overview

You might have to whittle out your own shims- - - - -the pre-cut ones aren't available at most places.

https://www.myautovaluestore.com/sealed-power/engine-crankshaft-main-bearing-shim-set-fed-fsm124s

Buyer beware!
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!