16v conversion

Does anybody know how to identify a 16v ecu and loom from a series1 gti ecu and loom? Ive bought a series1 gti with a 16v engine and box, and a car full of spares. Along with about 10 wiring looms and am not sure which are the 16v looms and which are the 8v looms. And the same with the ecu's.
Cheers