Thoughts on buying used differentials
 

I have the 4.3 Torsen in my car and want to upgrade to the 3.9 (at least). Right now, I have a bead on two used differentials from salvage yards. One is cheaper and within an hour drive to me and the other will have to be shipped from Texas to California. Specs:

2001 6spd, locking - 90k miles - $350 and local pickup
2002 6spd, locking - 40k miles - $450 plus shipping

Knowing that both of these are still cheaper than buying a new one, which one should I get? I know the more expensive one has the mileage advantage, but it is probably going to be $200 more expensive. Your thoughts?

They're both cheap, so you're lucky. I'd get the less expensive one, and never think twice.

buy the cheaper one and post a for sale add with a link so someone else can benefit from a $450+shipping 3.63 torsen...which is a good price

I am pretty sure it is a 3.9 not 3.636

well it turns out I was wrong on the location of the cheaper one. I thought it was a town that was close to me, but it is an 8.5 hour drive. So I will probably end up having it shipped as well. Should I be worried about the mileage on the closer one? My car only has 45k miles on it right now..

GAH! Now I find a '81 626 carrier (3.636 ring and pinion) that is 4 hours from me and they only want $75 for it. So do I keep my parts and swap out the ring and pinion or buy something already assembled. From a geek points perspective, I would love to do the ring and pinion swap. Especially since it is the gear ratio I really want. Any sort of special precautions I need to consider with this? I know I am going to need a new speedo gear as well.

sorry, just searched around a bit and the 3.636 rear was only in australian 6speeds, USDM had the 3.9, sorry again, i just forgot...
if i was you id go for the 3.636 since that was what you initially wanted...

please PM me the info on the 3.9's if you aren't gonna jump on them and nobody else has dibs

well it turns out I can't pass up on a cheap opportunity to get the 3.636 gears so I bought the 626 carrier. Let's hope it is good shape! At least the guy said it was stored indoors for the entire time he has had it. If anyone else wants the information the 3.9 carriers I found, PM me and I will gladly reply.