Power fc help into fd
 

Hey guys can anyone help me out here i have a 1997 s7 fd jap import and i am chasing a power fc for it what part number do i need as i know one for sale but the part number is not on the site listed but the guy had it fitted to a 1996 fd?
the part number on the one i am looking at is pfc fd3s4 020-2803 an on the controller it has fcc3 020-12617
Thanks guys
Also how do i tell if my car has a s6 harness or s7,8 engine harness as it has had a s6 engine fitted due to original replaced and unsure if harness got changed