Interchangibility of S4 and S5 NA Differentials.
 

I did some searching and cannot find the answers to concerning S4 and S5 NA rear end interchangeability questions so, here they are.

Will an S4 NA axle bolt into an S5 chassis? Are S4 and S5 axles interchangeable?

Are S4 and S5 NA drive shafts interchangeable?

What about just the diff out of an S5 going into the S5 case? Doable? S4 half shafts needed?

I have a line on an S4 NA case with a limited slip and 4.3 gears installed. I also have a spare S5 NA case and half shafts. The goal is this 4.3 gear set and limited slip in my S5 chassis.

Everything is interchangeable so long you stay N/A to N/A and turbo to turbo components. You cannot mix turbo and n/a components.