My frnd has a 2000 mustang GT. 4.6, sohc PI. now he hydrolocked the son of a bitch. We had a 95 cougar sitting out back and since i have heard that you can swap the parts over i was like this will work man so we got it all together RUNS AWESOME!!! but here is one problem. the passenger head, there is a water passage that is hangin off the side of the block. now can i take this head off and plug that hole up???

As long as the coolant is flowing normally though the engine I don't see why not.

You should swap the heads from the 00GT to the older 4.6 engine, you'll have a compression bump and make more power. Plus you won't have any weird shit hanging off the head.

that is what i have done. the block is from a 96 cougar. sohc 4.6 and the passenger side head has a water passage that is hangin off....... so idk do the heads have to be reversed to get the right seal....?

Can you post a picture. Sounds really random.