Ok fellas i now have an Rs Turbo doner car.

Heres my plan, as the doner car is not being scrapped but sold on i need to do a swop kinda thing............

1988 Rs Turbo Lump into 1985 Xr3i engine bay and 1985 Xr3i lump into 1988 Rs engine bay

Whats needed to do this?

I was thinking about getting a S1 loom and putting that in the Xr?

Will the Xr lump run on the Rs's old loom in the 1988 car? Even tho there is wireing for the ecu's which wont be used?