Hello, I'm considering swapping out my 2-spd Powerglide trans for an automatic (preferably 4spd). My car is a stock '68 convert with 350ci, 2-bbl with A/C, P/S... The car is the final stages of resto and all orig with 50k on the clock, numbers matching). I want to be able to take long trips, running highway speeds and also make the car a little more responsive. I was wondering what everyone would recommend. TIA!