Consider a Gear Vendor overdrive. Thats what I did to my 3600. I have the SM420 four speed, and I was able to find a 4:10 out of a 71 Chevy c20. I end up with a final ratio of 3.2:1, and with my 235 I have plenty of power to cruse hwy speeds with ease. I average between 17-20 mpg Hwy and I am very happy with it. I think if you go too high rear end gearing you will suffer in starting in second gear. 1st gear is the creeper gear and not practical to use except for parades. I run about 2100rpm at 55 mph and it is a pleasure to drive. I can go faster if I need to, but I don't live where the speed limit is higher than 65mph on the four-lane highway. So I use 2nd, 3rd, 4th, and 4th OD for my driving. Around town under 30 mph, I don't use the OD.
Last edited by lumbersawyer; 10/14/2024 2:11 PM.
