The 7 1/4 rear is not as weak as most people think. I have been running the same 3.91 SG 7 1/4 since 1974. It has been in 5 different street/strip cars. Now resides in my 66 Valiant that runs mid 13's at 94 mph in the in the 1/4 mile. Has slicks, and does 1.79 60 foot times. Also have a 4.56 SG 7 1/4, and a 5.13 SG 7 1/4.