Engine Swap

Quick question i just picked up a 1990 jetta from a family friend and I am considoring swapping out the engine this fall but i am wondering wht the most powerful engine i can fit into it is, without changing too much of course... i know that Scott (previouis owner) has a 93 Corrado Vr6 and i was wondering if that type of engine might be able to squeeze its way into my engine bay, if not maybe a 1.8 turbo? i unno any help would be greatly appreciated.. I personally Until recently put all my time into learning jap vehicles such as my old civic and my dream car(supra) so yea thanks in advance


Benn