rear disc brakes on 8 3/4

unfortunately i bought my axles from mopar madness on ebay approx 6 or 7 years ago. if i remember right they use yukon axles. don't know the exact measurments. don't even remember any conversations.

well, do you know how much off set i have to measure?
Again BBP axles i have with redrilled drums from my previous stock sbp axles