Easy to set the preload with a fish scale, I use one from Cabelas.Mike
X2 - I been doing the same & never a complaint re: loose or tight bearings once I have had a wheel/tire mounted - I go to the tight end/# or 2 over with 315's/35's, just because I'm spinning bigger donuts, but that may not be optimal.
Anyhow, the fish scale is a very legit way to set the preload - good advice, Hanson.