i believe that the head you put on, does not evenly line up with the block you have.

some of these heads have minor differences but make a huge difference

in some instances, people have put a silicone filler in the hole that is not covered. if that does not work, check your water pump, but it sounds like the block and head do no line up.

fyi, to save the headache, it would not be too hard to find a head exactly like your original one. they are everywhere

hope this helps!