I know that the S5 intake bolts onto the S4 except the 2 halves are not interchangeable. I'm wondering if the S4 throttle body will bolt onto the S5 upper.

Basically I can score an entire S5 intake for less than 1 air bleed socket (of which I need 2) and was thinking of using the S5 LIM, UIM then s4 throttle body and fuel rails. Or will I have to use the S5 fuel rails?

 

yes on throttle body, use whatever fuel rails you want

 

+1

 

the TBs swap over , there is a minor difference in length of one of the studs
ie, the s5 TB onto s4 UIM will need a few washers in one corner

as for the fuel rails , if you put the s4 secondary rail onto the s5 LIM you have to slip a washer underneath the mounting tabs to jack it up just a little to prevent crushing the injector

similarly s5 secondary rail onto s4 LIM will be 1 or 2 mm looser pressing onto the top injector o rings

 

Awesome! Thanks everyone!