I think he means how much water pressure, and the answer is enough to make it leak if you don't fix it right! These young guys.......ok, my advice, just figure it out, go on Google and read how to's........then do it, fixing a stud is a 15 minute job for God's sake. And I agree with the post above, you need to do a LOT more "hands on" work before you even consider an engine swap. And buy an overhaul manual. (Ebay) Engines don't just fall in place by themselves......... just my