I've been searching and can't figure this one out. I'm looking into 3.9 final drive gears because I am staying NA and hear its one of the best NA mods you can do. However, the only place I can find selling the setup is 350evo.com (here) and its going for $900. Is that really what it costs? Do I need both a ring and pinion? *So confused*

 

try www.z1auto.com thez have one from CENTRAL20 in japan and it goes for about 500$
i received my order a few weeks ago but it is not installed yet

 

I'm looking at it now, here.
But has anyone tried these out before? I've only heard of people using 350evo 3.9's.. and what is the deal with these install kits that they offer? My build date is past 1/05, and they say I should get the install kit for another $288??
I would be getting this installed by a very good installer, would I need this extra kit?

 

Bearings, shims, gaskets, washers, etc... Nissan recommends replacing those with every rebuild of your differential. Those are the parts included in their rebuild kit.

You also might want to take this time to consider replacing your LSD. The ring gear surrounds the diff, so to replace the LSD later would be doing the exact same work twice.

You're not 5AT, right?

 

Nope, 6mt. My car only has ~7k miles on it, do I really need the install kit?
And as far as the LSD, I'm not getting into drifting or racing any time soon. What real advantage would it give me?

 

I wouldn't advise doing the rebuild without them. You could probably get away with it, but I wouldn't do it. I'm doing a full rebuild on mine.

A LSD will be dependent wholly on how you want to drive the car. If you have no intentions of taking the car to the track, a LSD could potentially be overkill, but a good LSD will improve your traction and ability to transfer power between the 2 wheels. The car will be better with it, than without.

If you decided to add-on later, you would have to do the entire rebuild process again. The majority of the cost of labor of pulling and replacing the pumpkin and the rebuild time to do it twice, would cover most if not all of the cost of the differential.

Take a look into the Nismo LSD, I think it includes the parts required for a full pumpkin rebuild. That should cover everything you need. Worth thinking about.

 

Eh.. it just seems like its going to be more expensive than I thought. Either way, its looking to be $800-900 w/o install. 3.9's worth that much?

 

I certainly hope so! Especially since I'm paying a lot more than that for my complete rebuild.

I've never heard anybody who has done the mod post that they regretted it. Nothing but good things other than the CC issue.

 

you dont need both install kits - that depends on mileage.