Valvoline VR-1 vs. Lucas Hot Rod oil

If you have a motor with tight bearing clearance. I don't think you want to run thicker oil like 20w50
I was just wounding the 10w30 oil. What clearance your bearing should be?
I see people set up motors from .0015 to .0030. Just wondering if you are on the tight side or if you are the loser side of clearance does the weight of the oil matter?

20w50 worked fine in a 96 Neon 2.0 DOHC 4 cylinder in Maryland for 20 years and 250,000 miles, still runs like new. I'm sure we are all overthinking this oil thickness thing.