Cooked the rear in my Dart!

Ive got 3 or 4 good 7.25s you could have,an one of them for sure is perfect.Its still in my 71 dart im driving now,with brand new drums,shoes,wheel cylinders,and hardware that somebody installed before i bought the car.I just drove the car on a 300 plus mile trip and the rear seems perfect.Although its not gonna live long be hin my 300 plus hp 318 if i dont get the 8.75 swapped in soon,lol