Nice experience. My motor came from a guy who had just the same experience you did. And absolutely every time that things started leaking he would just add more. That led to overheating problems eventually which could not be solved. He sold the motor to me for fifty bucks and bought a stroker. I pulled the freeze plugs on that bad boy and commence to chiseling and digging and blastin that crap out for days till I got what I thought was most of it out of the block. It ran cool as a whistle after that and basically I just put a good radiator (same one I always have just an old stock slant 6 radiator) a good water pump and get hoses on it. Oh yeah and sealed it correctly. Just use water in a little jar of Redline water wetter like always.