Here are pics of the two diffs. Looks like they are very different. The left is the 79, right 83

Take the large plate off of the 83 and then have a look. All you can see is the mount in the center, can't really see the diff at all.

Take the large plate off of the 83 and then have a look. All you can see is the mount in the center, can't really see the diff at all.

Well I was wondering if that was a cover or part of the diff. Dang

Here is the 83 diff with the cover pushed away

Here is the 79 diff

What do I have here guys?

The small one is an R180. That car should be an automatic. The large one is an R200, that one should be a manual.

R200's are common enough. Should be pretty easy to find one that is in good shape, and it is MUCH cheaper to find a good one than to rebuild a bad one. Bearings are expensive and I believe the ball bearing on the pinion is NLA. Gears are NLA except for a few ratios you probably don't want out of Nissan Motorsports, or the hyper-expensive OS Giken gearsets.

The 83 is an automatic but its a turbo.

The 83 is an automatic but its a turbo.

It's odd that a factory turbo car would have an R180. I don't believe that that is the standard diff.

It's fairly easy to swap between the two, from my understanding. Something needs to be turned upside down and you might need a new rear diff mount, from what I've read. But the necessary bolt holes are on the car already. Might be easier overall to get an R200 from a wrecking yard though.

I've got a really quiet r200 that I'm selling- I'm going with a subaru diff. My diff is a 3.54

The Turbo car lived some of it's life as a Chevy V8 car so there is no telling what else was swapped. How much for the r200?

I was asking 200$ since it is all cleaned up and painted and has all the studs and nuts and stub axles. I might be able to help with shipping since you leave fairly close.

One for sale on hybridz.org - http://forums.hybridz.org/index.php/topic/104039-r200-diff-sale-336-390-lsd-378/page__pid__972945#entry972945 Shipping could cost you though.

The R180 should work fine if you don't beat on it. Datsun used it on a lot of models even though the R200 was available. Who knows maybe it's inherently quieter.