Originally Posted by snrusnak
I don't know a whole lot about the transmissions I just know the 68rfe is the diesel transmission and the 66rfe is basically the 68rfe gearset in a 545rfe case and is for the hemi n the 2500's. That gearset from the 68rfe or 66rfe is a much better gearset than the one in the 545rfe(ratios are spread more evenly, lower first gear, and taller final gear), and it is supposedly stronger which should be obvious since it's from a 2500 ram not a 1500 ram. I'd be really interested in more info on the transmission work, and cost, as I'd be interested in it myself just for the better ratios. Thanks and good luck with the truck!
The strength of the 68 comes from the number of frictions it uses over the 45. I have found a way to put even more frictions in the 45 then come in the 68. I also rebuild the pump so that it produces up to 250 psi and modify the valve body. When you put all that together you have a trans that can handle more TQ, that shifts hard, but not harsh.