The ZC Exhaust manifold goes 4-2-1 rather than the a6 or a3 4-1 manifold. what that means is the exhaust pipe in the car will not match up to the zc manifold. you can use any othe d-series 4-1 manifold and it will match up to his exhaust pipe. And for better performance, he can use a zc or z6 exhaust pipe that connects the cat to the manifold. Or while he's at it, tell your friend to just go ahead and get a descent header. it's only like $100 for a descent header off ebay. but yes, any d-series manifold will bolt up to the zc, so you can fix your problem with bolting it to the exhaust pipe.