8.25 to 9", how much did you need to shorten your ds?

Okay I got a disc braked/moser shafted/31 splinr 9" out of a 70s F150 from a buddy. I am wondering how much longer the pinion is on a 9" and what size u-joint do they use? (the axle is not at my house) Just needing to know how to get my ds hooked up pretty much and for cheap cause I am upgrading t-case soon after this anyways.