lsd
 

will a s4 rear end and drive shaft fit on to a S5 that has a S5 tii swap? or do i have to use the S5 parts?

Non turbo? Turbo? rear end... what exactly are you asking?

you need to post more details if you are expecting an answer

The turbo & NA have different pinion flange & half shaft diameters.

s4 turbo rearend to s5 turbo is fine
s4 na rearend to s5 turbo requires special mazdatrix driveshaft.

Sorry I didnt make myself clear. But Im want to see if a S4 Tii rear end will fit my S5 na.

don't think so, you'd have to do a full TII drivetrain swap.