More work on the Plum Crazy GT

OK, so, I am thinking that I might leave the 273 that is in my Plum Crazy Dart, in there and just clean up the motor and maybe install little tidbits like electronic ignition, 4-barrel manifold and a 600cfm holley, new wires and cap, and other easy stuff like that. Please give me your feedback! I have a very nice 273 that was rebuilt by a fellow member here on FABO, but that one might have to stay in my white 64 GT to be sold after my Plum Crazy one is done. Also, should I keep the pushbutton or switch to a 4-speed, like I did on the other one? I would love to hear from any or all of my fellow FABO brothers and sisters on this.