Another LSD question

[CU Zcar]

I've got another LSD myth I'd like you guys to either confirm or dispel. I've heard that the front differential of some Nissan (or other imported?) 4x4 trucks is swappable into a Zcar (i.e. an R200 or other R-series diff flipped backwards). Fact or fiction? Also, I wondered if it was possible to swap just the carrier (LSD unit) out of any Nissan (or other) solid-axle LSD's into an R200 case.

Thanks for putting up with my ignorance!

[SleeperZ]

I believe the Nissan truck unit is an R180. Some of these have ratios of 4.38, and none are LSD.

[Modern Motorsports Ltd]

Their are high ratio front axles in some 70's and 80's specific Nissan trucks which are R180's and are the common source for higher gears/diffs (4.38's and 4.6X). The rear of a later model solid axle rear is an LSD R200 setup that can be used for IRS-axle via word of mouth (ie. not confirmed, they do have some R200 LSD truck rears)

[johnc]

The model year 1980, 1981, and 1982 Nissan 720 4x4 pickups had R180 diffs in front with 115mm gear ratios 3.90, 4.11, or 4.38. I've heard rumors of the 4.6 gear but I've never seen one. I've also never seen a LSD in the front of the 4x4 and I'm pretty sure none were ever offered from the factory.

 

And, no, you don't have to flip them over. Nissan engineers were "smart" enough to have the output shaft from the transfer case turn in the correct direction.

[Guest Aaron]

If the diffs in come 4x4's are R200, then it seems to me that the LSD's and Detroit Lockers that are available for them should fit in our R200's. I have never been inside of one of these diffs before, so I am speaking totally from speculation.