Did you replace both the UPPER intake gaskets and the LOWER intake gaskets on this two piece manifold? Recheck your work. With a mirror try to locate the 'source' of the leak before taking anything back apart, just to be sure you know what to look for when you get back into it again. May be just a hose. Water leaks can be tricky, leak over there but show up over here!
Thanks, it helps to get all the information we can.