I recently put extractors, wade 1004 cam and reco EF XR motor into my car (1998 EL fairmont using Ghia ECU) and when the car revs if I put the clutch in or put it in neutral the revs hang and take a while to come down. My brother disconnected the stepper motor and it helps the rev problem but then it only idles on gas and not petrol. Does anyone know what is causing this? Not sure if its related but the engine doesn't seem to rev as cleanly and quickly as my brothers EB with an AU engine either, plenty of power just takes some time to get up in the revs.

umm im not sure about the steeper motor being the problem, i sort of had the same problem with my focus but it also didnt have a nice idle.
first thing i did was clean the throtle body and the problem was fixed.
you can buy throttle body cleaner but i just used carby cleaner since i had it lying around.
not sure if it will be a fix but well worth a try