I just spoke to Larry Millwee at Clifford Performance and he said they had a Jeep six in with 4.56:1 rear axle and the guy was complaining about top speed problems of 55 or 60 with 30 or 33 inch high tires and the guy was going to change out his ring gear/rear end. Larry said they installed a computer tuned weber TBI injection system and electronic ignition and now the guy can do 70MPH in SECOND GEAR! He says he's got the whole set up for a Chevy 54 half ton 235 and said I should've talked to him first before changing my rear axle; said the original 3.90 torque tube would have worked perfectly well with a fuel injection and tuned system and even with the original Muncie three speed. (cost is about $2,000 give or take)
Just offering this experience to you all to let you know how many ways a person can go here!!!
I think someone was yanking your chain a bit on that one. Changing to a TBI iduction and electronic ignition is not going to change the rpm that the engine has to turn to get a given road speed with a specific ratio. All it's going to do is maybe give it more power to get there, and most likely use more feul when it does get there. It would still be running the same rpm. Only way to lower engine rpm at a given road speed is to either 1; change the final drive ratio, or 2; add an overdrive gear to the transmission.
