Clearance with dry vs wet clutches

I have a few of each spring and I'll measure them to compare. When I get my new mill up and running, I'm going to try early/late piston/spring combinations and then mill each piston for perfect clearance. then the spring won't be too preloaded; and the piston won't be coming out too far. If that's not feasible, then I'll tig up the pistons. Or find a thrust washer with inner tangs to lock into the piston to take up the clearance. But, all things considered, I would rather put a spacer under the piston like some do on the th350 intermediate and run the proper clutch clearance, than have that extra slop in there; which contributes to a delayed forward clutch engagement. That might cause extra wear. I don't see how ordering a new piston without having exact clearance knowledge beforehand..wouldn't accidentally preload the spring so much so that it can more easily reverse itself. As it stands now, placing a spacer under the piston of the exact thickness seems to be the best quickest solution. I would prefer .025 on the early over .048 on the late. Thing is, the early springs seem to have a rep for breaking more easily. But if I do find a lot of variation in the spring heights, I'm going with the deeper ones. It's a shame that the extra piston/spring clearance doesn't contribute to extra clutch clearance.