So my 2000 mustangs 3.8 is on its last leg and i got to pull the tranny out to rebuild it(starting to shift rough) anyone know if its a good idea to swap a 4.6 in it, one of my buds told me they use the tranny and id need to redo my rear end but honestly no clue about it.... so any ideas

 

Swapping in a 4.6L is a pain. Usually it's suggested not to waste your time if you haven't done it before. Best way is get a wrecked GT and start swapping EVERYTHING over. The motor is about 15% of what you have to swap to get it running correctly.

Do some searching in this section and the 94-04 V6 section and you'll get more answers.

 

Swap itself is easy as long as u have all the needed parts.