I have had threads here before about transmission upgrades, but now I have a little cash & will actually be doing this in the next 2 weeks & need some useful info. I know that my 2001 3.9 auto 2wd started life as a 5.2 with the 2 front cylinders chopped off (sort of). I heard that the 46re will bolt right up in place of my 42re, but I will need to have the drive shaft shortened & balanced again. One local salvage yard told me to only use a tranny from a 2000 or 2001 or I will have issues. Any heads up on this? I am also keen on having the wired connections bolt right up without much if any modification. If any of you have done this, please share your experiences with me. Also, if any of you have the tranny I am looking for to sell, I am in the market. I want the PACT unit, but I don't have PACT money for now. I imagine I will also need the crossmember with the rear mount bushing to make it fit in just right. Some local shops told me the electronics & the control module may not like the switch, so I am really debating having this rebuilt or upgraded.