# 300ZX posi rear end conversion?



## 240sxshadow (Aug 17, 2005)

I need a posi track rear end to compete in the autocross and drifting comps in the area. Well I don't need it but it sure would help. Does anyone know anything about the 300zx conversion? Or is there a better option? Thanks for your help.


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## Kouki S14 (Dec 24, 2004)

The 300zx carrier bolts up differently. Go with an aftermarket lsd or at least a factory vlsd out of another 240 or a mid 90's infiniti j30.


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## 180SX-X (Sep 21, 2003)

i agree with the infiniti option..does phantom grip make a kit for the 240?not as worthy, but a less expensive option..


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## BoostedSE (Jun 26, 2005)

yes but it sucks


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## sidewayz (Oct 6, 2005)

really sux get the j-30 or a silvia I think there the same ratio even. I think you can put the guts of a 300z in your stock housing w\ a little modification but you lose oil capacity.


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## 240sxshadow (Aug 17, 2005)

sidewayz said:


> really sux get the j-30 or a silvia I think there the same ratio even. I think you can put the guts of a 300z in your stock housing w\ a little modification but you lose oil capacity.


 Does the j30 bolt right in ? Do the axels fit? any major mods?


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## Matt93SE (Sep 17, 2003)

the J30 diff will bolt right in. 

the 300ZX NA diff is the same, BUT the flanges are different so the axles don't bolt up.. I tried swapping the axles as well, but they're about 2" longer (each) than the stockers.. so they wouldn't fit.

the 300ZX TT and J30 diffs both have taller final drive ratio, which is good for gas mileage, but bad for acceleration.

the 300ZX NA is the same final drive as stock on an S13 or S14, so that's my recommendation.... BUT the flanges are different so you have to swap the output shafts from a VLSD S14 or a J30 diff.

what I ended up doing was buying a 300ZX rear subframe for $500 and stole the diff, rear spindles, and brakes. sold the rest of the subframe ($250) to get some of my money back. then I went and bought a J30 diff used for $150.. swapped the flanges over from it into the 300ZX diff, and now I have an LSD with the same final drive ratio. whenever I finally boost the car and can stretch out the gears some without being slow as a slug in winter, then I'll swap the J30 diff back in.


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