1) Is it possible to just buy 3.53 gears from Infiniti and swap them into a 5AT? (or do I have to go aftermarket?)

2) All aftermarket stuff, liek CEntral 20 with 3.9s, says only for 6MT. Will only the 3.53s work with a 5AT, or do they only recommend 6MT because your top end will suck on a 5AT?

 

Don't bother trying to physically swap the 3.357 for the 3.538 gear. They're different thicknesses and incompatible unless you buy a new diff for the 3.538 and do a complete rebuild of the pumpkin. That's both expensive and complex. This is why 5AT and 6MT diffs are not interchangeable either.

It would be cheaper to find a pumpkin from a junked 6MT or swap with somebody looking for the 3.357, or even buy a brand new complete pumpkin from the dealer for $1250.

 

Gotcha.

by the way, how difficult is it to swap pumpkins - on a mustang it isn't that onerous, but not certain about a g35?

 

I believe you could put Quaife and 3.5 (or 3.7) in an AT pumpkin... Correct me if I'm wrong - because I've been leaning towards this... (although I just heard about a 3.5 w/OEM VLSD that I might do instead - cheaper).

 

??

Quaife

Part Number: 44.309.181
List:1495
Found: $1313.99
Engagement:Gear
Notes: The Quaife differential is a drop in installation for the "open" diff base model 350Z or G35 6MT. If you have the factory Nissan VLSD, you will also need a set of stub axles from a base model open diff 350Z. Nissan P/N 382200 AR000 Axle Flange

 

There's 2 different versions of the Quaife ATB diff. One for the open diff 5AT pumpkin and one for the open diff 6MT pumpkin. 44.390.180 and 44.390.181.