I 'm going back to a 195 stat to get my car to 200 degrees the running part as stated is from a fuel problem or that edel carb. Recently it has been cool in Pa and I have trouble getting to 180 even with 4.30s Your problem is mainly fuel ignition related not from being at 200 degree's. By the way a factory Mopar radiator I have found to be the best ones of the bunch even out cooling the aftermarket aluminum rads. Search for a A/c max cooling rad for a big block Good Luck