OK- - - -I believe the 1950 models had either a "zero-pressure" radiator, or no more than a 4 PSI rating. Does the overflow line come from the filler neck above the radiator cap gasket, or is it incorporated into a canister high up on the top radiator tank? With a low or "no pressure" system, it might be wise to use a 160 degree stat. The only downside will be poor heater performance in cold weather. Be very sure the cooling system is clean and leak-free.
Jerry
