Originally Posted by JW51
Can the later precision fit bearings be used in the earlier blocks?

Possibly- - - -if the outside diameter is the same. It would be a situation of trial fitting and maybe shimming for the correct oil clearance, or maybe installing the bearings without the crankshaft in place, measuring to see if they're round, and grinding the crankshaft to fit the bearings. More than one way to skin a cat! It also might be possible to line bore the block for the precision bearings, if the OD is different.
Jerry

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