OK yesterday I removed the new radiator, all hoses. Water pump is brand new and is not leaking and is turning so I don't know what could possibly be wrong with it, so I ruled that out. I back flushed the block from the connection at the head. I flowed water through the radiator and as quick as I put it in at the top it came out the bottom, so no radiator problem. I ran rags through all 3 hoses and could find not blockage or anything hanging up. I then put the torque wrench back on the head bolts and was able to turn each bolt 1/2 to 3/4 turn before it clicked off at 135lbs, which is 5lbs over what the manual calls for. I had torqued the heads with the sequence specified when I rebuilt the motor and did it in 3 steps like it instructed. I was surprised it turned that much. After putting everything back together I went out and mowed putting it in 4th gear 2nd in the automatic range and ran it up hill to put a hard load on it. I'm mowing with a Rhino 72" mower. Even under this heavy load the tractor would pick up speed going up hill, which it never did before and it never got past 175 degrees. The good news is it only spit about 1/2 inch of overflow into my over flow tank. 1st time it hasn't overflowed since the rebuild. I could only mow for 20 minutes but I pushed it hard for those 20 and it never overheated or pushed any fluid out, like it did before. I can only assume that It was leaking hot gas into the water jacket previously due to the head not being totally seated? I don't know what else could explain the change. I didn't find anything wrong. I'll know better in two weeks when I take it out to mow for an hour, in the heat of the day. I appreciate everyone's help and I'm hoping my overheating days are behind me. I wish I could get the factory head gasket that I originally tore off the motor, it was solid metal, not the metal/fiber the new ones are. I've never had a problem with heads blowing by a gasket but now I have so I'll remember to heat up and then re-tighten before going out and really starting to use the new motor.