I did a lot of drag racing in the 60, 70, and 80's. I would not count out the 4:56 by no means. We are very happy with the 4:56 in our SSR. Still pulling hard at 125 mph. Nothing like the 4:56 four speed 1:1 ratios of the past. 70 and 80 on the E-way is a walk in the park low RPM,s and very respectable fuel mileage. You got to drive one to see what I mean. Good luck on your install.