k i know i'm a noobie and before any-one says it I HAVE searched!
just wondering if there would be any benefit in putting a 86kw red and black top head on a gze block? say with everything stock including the supercharger?
That depends. If the GZE is a big port, then the 86kw head will be identical to what you already have.
It its a smallport ZE then the 86kw will have slightly more cam lift and duration which could improve things, but then your intake manifold won't bolt up.
In short, no its not worth it. Bigport cams into smallport ZE head may be, but that's still debatable. If you have further questions search harder, as it's been discussed before.