What lifters are you using?

I ask b/c some of them (the anti pump-up ones) will allow you to run a much tighter setup.

My SB favourite are the SpeedPro HT2011R, which are supposed to be installed with 0 (zero) preload. As in: tighten things down until the pushord stops spining/turning between your fingers.

Prior to switching to my current hydraulic roller setup that's what I used, and loved them!