Sure grip 7 1/4 strenght?
I would just add my 2cents, switched my 65 formula s from a 7 1/4 to a 8 1/4 rear for the reality of being able to put 14 inch rally wheels and better grip! I drag raced hard back many years ago with a 66 cuda 318 motor ran high 12's finally blew my 7 1/4 rear away! It was the weak link for sure! I had a 8 3/4 rear built for it and it became the strong part of the car! My current 65 runs strong and also 318 not quite so fast yet as it is just a road car, fun in the sun! However, we went to the better rear for a good reason as safety and potential speed down the line was our ideology when building this big boy toy! Also the bigger rears have more parts to play with!!
65Cudalover