Change the pump and change the thermostat to a 180. The housing will be fine... Yes it has a smaller port on one side, but so do many of the other (flow balanced) aftermarket housings.... 440 Source just happens to be the smallest.
Bottom line... I ran a whole series of controlled bench tests a while back using various housings and pumps...and the 440 Source housing with a stock pump flowed just as well as the stock Mopar housing with the same pump. The 440 Source pump however, was the dog of the bunch, especially at low rpm's.