Would it be better to rebuild the trans on a 420a motor vs buying an upgraded one? If so what is the difference between the two.

Honestly, I would get one from the junkyard. You can rebuild yours but these trannies are pretty stout. You might want to price out a rebuild first.

As for upgraded tranny's, we really don't have one available to us. There are upgraded parts for the diff (like diff pin savers and Quaife's) but really not much to choose from. There is a gentleman on neons.org who is doing some kinda neat things with tranny's. I think his rebuilds start at $900 plus shipping.

i got my 3.55 rebuilt for $400, but i put the case halves together and such. cottman transmissions

Originally posted by 420agreenvilleSC
i got my 3.55 rebuilt for $400, but i put the case halves together and such. cottman transmissions

Hmm, really? What did that include? How did they set preload on the diff bearings (I'm guessing that they didn't, lol)?

Didn't ask specifics. I just dropped off the 3.55, they ordered the rebuild for what parts were needed, i picked it back up. I figured if it had a warranty on their work, I didn't worry. No issues so far. 1st and reverse are hard to get into sometimes, but it's getting better/easier. I guess it's part of the break-in

i think hahn says are trans will hold up to 450 hp no prob so no need to upgrade really

Ya i wouldn't upgrade it unless you have the money to put in into and are deff. going to keep the car for race or track purposes. If you need a new one, just do a swap. If your tired of the cheap paper backed synchros in our tranny's then i suggest upgrading to a better one or doing the rebuild and getting it double synchro although i can assure you this is very costly and will probably run you as much as the car is worth.