I'm running a 260z with an R180 and was wanting a higher rear end gear ratio. In my search I found that ring and pinion kits for nissan trucks with an r180 front diff are available at a much cheaper price than finding one classified for a "Zcar r180". Does anyone know if you could use these and swap them out in a 260?

The 3.36 rear gear in the back of a manual 240Z is about as high as you're going to find. If you want a lower ratio like a 4.11 or something like that, I think the easiest thing to do is find a truck in a JY and pull the front diff. I don't believe the gears are available anymore, I remember a couple years ago when Nissan Comp moved to TN they sold off most (all?) of their old gearsets.

If you could find the gearset there is another issue too, which is that in 76 (rough memory there, might be wrong), the ID of the ring gear changed, so if you had a 260 I think you'd need the carrier from a later diff as well. So again, finding a later diff with the ratio you want is the way to go.

Later Nissan cars used the K diff which had 4.11's I think, and you can use a Subaru STi diff with some of John Coffey's adapters and get yourself a 3.90 with LSD that way. More info on the K diffs here: http://forums.hybridz.org/index.php/topic/49194-differential-cv-lsd-hp-torque-r160-r180-r200-r230-diff-mount/ and John's parts here: http://forums.hybridz.org/index.php?/topic/78123-subaru-wrx-sti-r180-side-axles/

Edited August 23, 201014 yr by jmortensen

4X4 gearsets are all going to be 4.11 & higher(numerically).Even here is Az.,ealry 4x4's are far & few in-between.

Agreed, but the K diff out of the cars is still pretty available and the Subaru diff with the LSD is looking better and better all the time.

FYI.... Nissan Motorsports has one new R180 ring and pinion left. 4.88 ratio 115mm ID ring gear.