I do not recommend 5.13s for your car.those are race gears.
I drove on the highway with them for 2 hours at 60 mph with the tach at 3700 rpm. I also do not recommend using a power glide in a heavy car that is driven as a street bracket car.
If you can afford a 4 speed auto and 3.73 gears you will have a fun car that can travel.
Thanks tech for the back up.and Hi rice,where you been?