[alanwoodieman]

leak is really coming from the threads on the stud, one a new stud installation I use permatex #2 non hardening on the studs. only way to seal the studs is from the water jacket side. on a problem like this I use the old style pellet stop leak from barrs, put it in run the engine until hot and then stop the engine and drain out all the coolant and barrs leak. save it for now, leave over night then fill up with water and run engine. I have had to run the solution thru a couple of times to make them stop. then drain and refill with your antifreeze