Wheres theres a will theres a way, MK3 gearbox will make your life easier, ive got a S2 rad and IC in my MK3 cabby, if you use a S1 rad it is very simple to run water cooling off the standard rad, just pipe work. piece of piss to fit to fit the S2 rad though, engine mount is the same, gearbox mounts are different becuase the box is different.

What do you think a S1 is? A MK3 Escort i believe