I feel the main bearing design also makes a difference. The quality of crank also. As well as your choice of weight in oil.

I run 30wt max oil. An HD bearing and .0025" on a 2.500" main. 360mopar and 351ford mains I run .003".

Engines running full groove bearings with 30wt I'm not scared of .0025".

Big block mopars move around more and have heavy assemblies. Does that reason larger clearance?

Career best 8.02 @ 169 at 3050# and 10" tires small block power.