I also swapped my 3.08 to a 3.45 in my Sd1. Really does make a difference and can still reach max velocity of 150.
I tried a 3.9 out of a 2 ltr once. I just screemed all the way to 120mph in 5th. The axle didnt last too long either!
Also i think Perry runs 26" dia tyres which is going to give him longer legs.
Just done a check 26" tyre, 1:1 in 3rd auto, 3.08 axle gives 125.57 at 5000 rpm and 138.13 at 5500 rpm.
Seems a good ratio to me after all
