Like I said before, I agree, the T-stat is probably at fault for the temp variance... however, the radiator worked fine with the old motor. Should it be clogged a week later (allbeit with all new fluid)? Possibly, but I still don't know why I have air in my system.... i've test driven it about 15 times and each time it has the same amount of air bubbles that seem to come out of the fluid reservoir... Something is pressurizing the coolant. I think I might know the answer, but a reputible engine builder should know how to correctly install head gaskets right? Can head gaskets be bad brand-new? Sorry, for being so candid, but after working on this motor day and night for a a few weeks and spending quite a bit of money on parts, I'm about ready to burst....

Paul