My roommate and i are setting putting a detroit in my 9" which I pulled out of a 79 f150 with 4.10's. I decided to run that ratio rather than shell out more cash right now. We used the same thickness pinion shim as was already in there, set the backlash at .008" and ran a pattern. The coast side looks good, but we don't see any pattern on the drive side... at all. It's as if it's not even touching, kinda unnerving. So I did a little research and stumbled across something in Yukon's install manual that says you shouldn't pay attention to the drive side pattern when setting up used gears. I don't know how closely to follow that rule and I just thought I'd ask you guys before calling up the local gear shop and hassling them about it. Also any insight on the "wack" pattern would be appreciated. Thanks
-Adam

Go search the Jeep section for the TOTW about setting up your own gears. There is a lengthy discussion about this very same thing (in a dana axle). It was pretty much agreed that you should use the coast side for setting the pattern on used gears IIRC.