What transmission and tire size are you running? Since this is a transplant please show some pictures ect. Big intrest in this subject.

 

Agreed I'd love to see some pics. I have been thinking about doing the swap for a while now.

Chris

 

You really invest in a 5 speed with 2 ODs like the autos have because there is no reason you should be running 1900 RPMs at 60-65. Especially with 3.55s

 

Yeah that seems a little high. When im doing 70 its right at or under 2k and i have a 4x4 with 3.92s

 

At those RPMs, it sounds more like the older 48RFE auto than the 5spd manual.

After '97, the highest gear option I've found is 3.21. I don't know if Chrysler changed the 9.25 12 bolt rear after '97 or not, but you can get as high as a 2.71 ratio labeled for pre-'97 rear ends. All else being equal, it appears ANY gear set sold for a 9.25 will work, regardless of year, but Chrysler never put a ratio higher than 3.21 in any of their trucks. I think it's a testament to the engineering of the 9.25 that it has held up to the torque output of that Cummins without breaking so far. Anyhow, you can get the gears here: http://www.drivetrain.com/parts_cata..._pinioins.html