Originally posted by OnlyOneDR:
The transmission and flexplate get ditched for the new manual and clutch assembly. The front cover for the manual t-case has a lip on it for lubrications (autos don't because they "bathe" in ATF), so that cover needs to be changed.
The interior pieces aren't cheap, when I converted mine to 4x4 (stayed with a 5 speed) I still was stuck spending $200 on interior bits because they were impossible to find in yards. As for the clutch hydaulics, there's a spot on the firewall for the master cylinder already and a through-hole for the linkage. Find a donor truck and get all the parts from one truck. The ECUs are different, you will be abandoning the transmission harness and I do not know if the rest of the wiring is the same (and I don't feel like looking it up right now).
No driveshaft differences.
Don't expect a gas mileage increase, as the autos have a taller overdrive for highway cruising that tends to make them more fuel efficient.
I'd consider a swap like that similar to my 4x4 conversion, if you are going to keep it a long time and are going to heavily mod it out (to make trading it in a waste), then it might be worth it if you get the parts at a good price.
So how many mechanical pieces are we looking at here? I know the smart thing to do is go online and buy the blueprints (which I've done, waiting). But I'm curious, could I simply find a manual V6 in some junkyard, get all the pieces I need, and let a transmission store do the rest? If I know what pieces to get, then couldn't I simply tell a transmission place to just do the work for me? It's also a 4X4, which I'm sure doesn't change anything, because from what I understand the two transmissions are the same.