3.50fd A555?

[TurboBuggy]

I should have my car back together in a month or so and im starting to look at options for my transmission. I have an A520 with the 3.50FD and an A555 with the 3.85FD, and I thought I heard that you can swap the diff and stuff to make the A555 a 3.50FD. I dont know much about transmissions so I was wondering how hard this would be and what the job would involve?

[mcsvt]

First thing to check is the year of each tranny.
They both need to be either 87/88 or 89. You can only combine 87/88 with 87/88 and 89 with 89.

Next I believe you need to swap the main shaft and ring gear from one to the other.

I think there is a write up on how to do it somewhere... I'll post back if I can find it :)

edit: Hell we have the write up and explanation of what you need in the KC!!
http://www.turbo-mopar.com/forums/vbarticles.php?do=article&articleid=61

edit2: I should mention that i have one in my Daytona and love it :)

[MiniMopar]

Yep, that's making a "hybrid" trans. If you take your time and keep careful track of how it comes apart, it's not that difficult. Having the FSM is helpful. Get a pair of knurled snap ring pliers at the very least.

Check to make sure the A555 is an 87 or 88. If it's an 89, you may have a different main shaft whose gears not compatible with the A520 shaft. Take the A520 apart first and inspect the main shaft bearing surface. If it is pitted or coming apart, just stop here. The shaft is done. Otherwise you need to remove the entire gear set from the main shaft. Do the same to the A555 and swap the A555 gearset over to the A520 shaft. Then you use the A520 diff or swap the ring gear off that diff onto an OBX or Quaife. If you are using the A555 case for the A520 diff, you'll need to check the bearing preloads on the diff carrier.