Well, for me I've become a fan of King in a drag race motor like most of us build. Clevite is a great bearing as are most that's out there these days.

I like King for a couple reasons in a race motor. First the bearing is tapered, so as the crank flexes, it's less likely grab near the radius. Second, they're really tough, and the normal crap flying around in the oil gets embedded pretty easily. They're also very forgiving in the ole no oil on shut down, start up ect. They also give a bit more clearance, if you're under the max housing bore size. Also seem to be more round after the parting relief.

As for clearance, .0035 on rods and mains for me, and no less than .003. I'd rather have .005 than .002anything, but that's just me.