All sounds familiar..I had posted here last fall with my 350 HO rebuild probs and I was running 225 as well. I installed a new aftermarket 4 row radiator and put in the metal sheilds on top of the radiator and it runs around 205 now. As the engine is breaking in it seems to be running cooler. I will attempt a rally gauge conversion next week to get a better reading. I will say this take your car into a service shop and have them take a heat gun to the engine that way you will know Exactly what temp your at. By the way my 350 HO has no take off power, I can't even burn rubber....seems like I gained HP at higher speeds only when I upgraded my 350 to the HO.