legacycentral bbs

K I have been searching for a 3.9 AT trans for 3 weeks now and no one has them. I keep finding 4:11's. so im just wondering, could I buy a rear diff that has 4:11 gears and just bolt that in and use a 4:11 trans? if that is possible dose the diff bolt right in? are they any other parts I need to know of? Any information would be greatly appreciated

P.s. if it weren't you guys and this site I would be soo lost, thank you

that will work, pretty easy swap IF the years you are swapping correspond. you might run into some wiring differences if you are doing a big jump in years. otherwise, the diff and trans should be all you need. I'd say change the diff fluid while you have it out. if you can resell your 3.9 then all going to 4.11 will do is cost you time. good luck and be sure to get your torque converter positioned in the trans correctly.