Dave, for what it's worth, I had a similar problem with a new-used oil pan on my '44 235. Put it on, it leaked. Put sealant all around it, it still leaked terribly. Eventually sent it to a "mechanic". He put it on, and it leaked. He said he finally learned from someone to "pop" the pan, to get it to the right shape. I'm not sure what that means, but it sounds sorta like a twisty, back-cracking sorta allignment thing. Anyway, what-ever it was, it did the trick!
Probably no help at all, but thought I'd throw it in! :confused:
-Michael