Does anyone know how hard it would be to swap a ZC into an 83 civic hatch?

it has been done but it's a lot of work. completely different mounting systems and whatnot. you'll have to gut the engine bay and start from scratch with the motor mounts and custom axles.

Any suggestion of a possible swap?

that depends on what you're looking to get out of it. what do u have in mind for the car?

I want something thats a better starting block that the engine currently in it, and something not carbuerated