wiring harness?

[abq]

hey guys i need all the information i can get before i buy a new motor. well i have a 1993 325is and the heads messed up. so i found this nice deal for a 91 525i non vanos motor but it doesnt come with the computer or wiring harness.

do i need a 525i wiring harness or 325 non vanos wiring harness and computer?

and last question is can i use my old wiring harness from my vanos m50 motor?

i need this information asap

thanks
abq