Little help with cooling system please.

69 Barracuda 318. This car is about 2 months new to me and I'm still figuring (or trying to) it out. Anyways the radiator is not the original one as it is a 26 inch wide radiator. Here is a pic of the numbers on the top.

Someone went out of their way to put this in there. The water pump is one of the aluminum ones.
. The temp gauge does not work so I have been keeping tabs on the temp with a temp gun. At the thermostat housing I get about 180 to 190 degrees and at the bottom of the radiator at the bib for the bottom hose I get about 100 to 110 degrees. And at the center of the intake near the head about 210. is this acceptable ? When I shut my car off it pukes coolant out of the over flow. Last night I put a new 16 pound cap on it and when the thermostat opened it burped coolant.
Any help appreciated.
Luke