Will a V8 4WD transmission fit a 2003 V6 2WD?

Hi guys I have a 2003 Toyota tundra sr5 with a 3.4 v6 2wd I was wondering if the transmission of a 4wd v8 would work with the v6 because all the 3.4 v6 have a lever to switch to 4wd and I can’t find one that has it electronically? Can someone help me pls.

 

Yes and no.
The transfer case is what shifts in and out of 4wd, not the transmission. A 2wd will not have a transfer case. But the transmissions will be slightly different.

The 2003 2wd transmission would be an A340E, while an 00-04 4wd transmission would be an A340F. I believe the difference is the output shaft and it can be swapped. But I'm not certain. If the 4wd transmission is from an 05-06 it's an A750F and it's probably not compatible without some serious work.
@empty_lord

 

A340E and A340F are “the same” transmission. (Notice I used quotations for a tranny reference again ) However, the bellhousing, tail shaft housing, oil pan and valve body are different. Those components will need to be swapped over from the E to the F. You also might find that the wiring harness is different and may require a repin. There’s a guy on here from Hawaii that has done this. Do a search and you’ll find his write up.

 

Swapping output shaft involves total disassembly of the transmission

 

Avoid the 00-02 4wd tranny if you tow a lot. It has a week planetary gear that wasn't corrected until 03+. I'm guessing that's not an issue since you have the weaker v6.

 

I believe this issue only exists if you tow in OD. My 2000 has towed heavy (7000# TT) in mildly hilly terrain many times as well as 3-5000# utility trailers often. Zero issues, still shifts smooth after 270k miles. Never towed in OD. These motors love to rev, don’t be scared of those rpm’s.

 

FTFY