Buddy
Powerglide is about indestructable used to rev my dads 63 chevy up and slam it in gear to smoke the tires and the trans never had a problem. I have a 283 with cam headers and high rise in front of the Powerglide and 354 rear in 65 GMC. It does ok no power till about 40mh then it's like two extra cylinder came on line. I've had it to 90 in low and think it would hit 100. I believe a 700r4 would be perfect in my truck and give me tire burning take off with great gas mileage on the highway.