Do aluminum block engines require additional main and rod oil clearances? If so, can someone explain why?

I've built a lot of (iron block) engines throughout the years and typically shoot for .002-.0025" on my Mains and .0015-.002" on my Rods. Obviously application and rod journal sizes matter here. I'm talking hot street engines, not full race.

On a race engine I wouldn't be afraid to run .003-.0035" on the Mains and .002-.0025" on the Rods, but I don't see a need for more oil clearance than that.