minimum clearance to springs?

I run 1/8" with 325/50-15s on ten inch rims,at 24 psi.But since these tires tend to rub on the inner fenders when cornering aggressively, the body keeps them off the springs,lol.These are actually my track tires, and I put 4 runs on them. Sometimes I bolt them on for show. I don't actually run them into corners much.
With my regular street tires, the 295/50-15s on 10s,I have run that same 1/8 too but since I know how sensitive the sidewalls are to abrasion, and there is some outboard room, I spaced the wheels out to get about 3/8 inch. This has never rubbed, even at 20 psi. The car corners pretty flat, and most of the time the tires are spinning and probably that tucks the sidewalls in too; it's great to have a torquey360.
I seen a picture in a magazine once where the guy could just get a credit card in there.This was on a 2nd gen Barracuda(68 I think) with a 451(IIRC) stroker. I tend to think he wasn't in to cornering.That mag was at least year 2000 or earlier.
I think the arch on the springs pays an important roll in keeping the body side-sway to a minimum; mine have very little arch.
For those guys recommending 3/8 or 1/2 inch targets, those IMO are pretty safe.