what loom for a 16v

right ive got the 16v in my mk1 but im trying to use a 1990 16v engine loom im doing this buy joining to the mk1 plug if you know what i mean , but ive been told that i carnt run a 1990 loom its got to be the pre 89 thats fits my 81 board .

so now im stuck i think i can get the 90 loom to work but im i just kidding myself lol . any feed back would be great cheers ash