I pulled the DORF 9" out of my 65 Cuda and replaced it with a LBP 7 1/4 2.94:1 SG from a 74 Dart Swinger. It stayed behind the 383 Magnumn for 2 years when I heard a loud grinding noise on the way home from work. I made it home and dug out my 8 1/4 - 8 3/8 hybred with 3.55:1 SG. Hung it on the springs ok. when moving the 7 1/4 around the garage, the left brake drum popped off and the brakeshoes were delamanated and that was the grinding noise I had heard.