Hello, I have a 2000 Ford F150 5.4. The transmission is about done for. I tow a lot with the truck and I know the 4r100 is better tranny for towing. I know it will bolt to the 5.4, but what all will I have to change to make it work? I found a tranny out of a 02' super duty 5.4 for 450 dollars that I wanna buy. Any help is appreciated!

 

The 4R100 is longer. You'll need to shorten the driveshaft, move the transmission mount, replace the computer with one from a 5.4L/4R100 truck, and modify or replace the wiring harness to work with the 4R100. It's a lot of work, this isn't a straight bolt in swap.

 

And you can't put a 2wd trans in a 4wd, and vice versa, without changing the whole tail housing. If you have to do that, you might as well just rebuild and beef up what you have.