alright, I am making some progress on my gear swap. my original 3.55 pinion has a -4 on it and my 4.56 pinion has a 15 and a 2.735. yukon instructions say to just start with the same shims that came off the original pinion however in the FSM there is a chart to figure shims based on the different pinion depth variances. thing is I can't believe the new pinion has a 15 variance as that is off the FSM chart. and I don't think if it is 2.735 they measure to the thousands, wouldn't it just be a 2 or a 3? any help? also these are hand etched markings on the pinion, and nothing on the ring gear to eliminate the matched set #.

 

Here is a link for using a pinion depth setting tool. Hopefully this helps.

http://www.ringpinion.com/Content/Ho...etting_Kit.pdf