1.4 16v into mk1 wiring help

Hi all, I am currently fitting a 1.4 16v intomy mk1 jetta. The engine has come out of another mk1 so bolts straight in no issues there.
The fist problem I have stumbled across is of course to do with wiring.
The problem is that the bit of loom that came with the new engine does not plug straight into my early fuse box.
I know I need a s2 fuse box but will I also need a full s2 wiring loom? I have cash waiting for both if anyone knows of any.
Cheers

Any1?

if you want a new fusebox then yes you'll also need to change the whole car loom, or splice later plugs to the early loom