What S4 internal engine parts are compatible with an S5? Are the three plates, stationary gears or rotors common between the two?

Thanks in advance for any help.

Walt

 

S5 rotors have a higher compression ratio, the spark plug locations are slightly different between S4 and S5 and the later S5 rear plates have a thicker casting where the older ones would commonly break under detonation. Otherwise, everything's basically the same.