[shinhed]

You can use the rear Z drum/disc brake, lug conversion with standard S13 uprights and you can used standard S13 rear brakes on the lighter Z32 uprights.

Edit:

I've never seen uprights corroded enough to need replacement but, if you're anal over the smallest things (like myself) you should sand it down, thoroughly clean and degrease it, use a metal pre-primer like Resto Motive's Metal-Ready and paint it with a paint made for metal (I recommend industrial grade Rustoleum hammered finish spray paint).

I used the same procedure on my subframe and my gutted interior except I used Por-15 on my interior and industrial grade Rustoleum on the subframe.