Well, strange looking "oil cooler" head or not, when I put it back in, leak slowed down (I didn't replace the gasket, was just testing) but now I have oil in the radiator. No water in the oil pan, oil level hasn't changed, no "milky" looking oil, just scum about 1/2 in thick in the radiator. I don't know why I thought I could re-use the oil cooler, if the housing cracked, I would figure it would go first, but I didn't see any cracks. Mistake. Ordered another oil cooler, and all gaskets. (Thanks for the suggestion, Dave, found a used one at the same place I got the housing, for about that same price. So I'm still into it only $160, plus new gaskets (which cost almost as much as the oil cooler). It ran fine with the replaced housing, with no smoke, had a little seepage around gasket where I kind of expected it, near the top where the gasket looked kind of "iffy". The oil pressure normalized when it warmed up, just like it always does, hope it's just the oil cooler, and not a crack in the block where the oil pressure is high and the water pressure is low, but I'm not ruling that out. So if I can get it fixed with this, and a "flush" to get the oil out of the cooling system, maybe I dodged a bullet. At least I can get it running enough to put it on a trailer and move it to my new place, 200 miles from here, where, if I need to, I'll replace the engine (short block, I hope). I always knew retirement would be restful. I can't complain, I have so much to do, I go right to sleep when I get a chance.