Hi Randy, there should be two "plates" or baffles, and two "tubes" with rubber bushings (that fit in where the water goes in and out of the ports), that all fit in between the water pump and the housing, sandwiched between, and should all be held in place, and should not rattle.

If you have all the components in place, and they are in good shape... there is no reason it shouldn't run at the right temp. There could be some air pockets in the cooling system (driil two small holes in the T-stat to let the air escape) the timing could be an issue (any pinging under load?) Carb running too lean? Do you have the front end baffels all in place as Bjorn mentioned?
Try a different T-Stat? These are just some of the issues you may run into as the cause of a hot running motor?

Try some water weter or similar product to help when all is said and done. After you find and fix a problem.

Good luck, I hope you don't have to sell it either! Where in the twinn cities are you? I lived in Bloomington and Burnsville for some time.

Brett - 67 Drop Top 455!