thanks for the info. So would it be best to swap out the pumpkin with lsd or just use my stock one and replace it with the newer final drive? Also, how can I tell if it's a base or not and was it available in 2002 models 350z?

Here are 2 slips that are the most comparable because they were on the same tires (stock 18s with pilots). Unfortunately I didn't record barometer numbers for the after slip, but notice that it was considerably hotter being in mid June. The first half of the run numbers are very similar, you don't really start to see a difference until the last half.

Before @ 2200ft temp 78 degrees Barometer 29.24

60' - 2.298
330 - 6.431
1/8 - 9.728
mph - 74.43
1000 - 12.576
1/4 - 14.967 (approx. 14.4 corrected)
mph - 94.59

After - @ 2200ft temp 95 degrees barometer unknown

60' - 2.289
330 - 6.341
1/8 - 9.622
mph - 74.89
1000 - 12.324
1/4 - 14.796 (slightly below 14.2 corrected only using altitude and temp, not terribly accurate)
mph - 96.88

im not really understanding the 14.4 and 14.2 times? What other mods do u have and is there any threads that showed other improvements on with this mod? I'm just trying to figure if switch from 3.3 to 3.5 is woth 700 dollars??? Is it possible to switch to a 3.9 final drive?

It will make you a little faster in the quarter mile, though it will force you to shift into fourth about 200ft before the finish.

It will make your car rev higher while cruising which will cost you about 1 MPG or so.

It can make a road course more interesting and fun as you will have to think and be more deliberate about where and when you are shifting.

Is it worth it? That's up to you. But I am thinking about switching my spare 3.2 to a 3.9 and installing it.

Also, it's important to remember that if you are thinking of rebuilding a pumpkin that it's not easy or necessarily cheap. There is a bit of shimming involved. Have someone with experience in rebuilding differentials do it for you.

I am actually talking with some one who has a 2002 350z pumpkin for sale. This unit will fit in my 05 g35 right? I really dont want to mess around with openning up the rear differential and swapping it out but if the 3.5 final drive does improve the quarter mile by .2 than I'm willing to get it. So truthfully, will I see that big of an increase in swapping out stock 3.3 for 3.5?

I would really like to see if a 3.9 will be better but I saw that just the 3.9 differential cost around +1g. I'm not too concern about losing 1mpg but that I see improvements. Thanks again for your insite and info bro.

I believe that if yours is an LSD it will bolt right up with a 350z that is LSD.

I'm not sure if a non LSD pumpkin can bolt into an LSD axle or not. Can anyone clarify?

Do the '05 5ATs come with LSD?

Does anyone know what looks different on a Non-LSD pumpkin? Is it easy to identify? I've only seen LSDs.

Also, how big is the pumpkin and how much does it weigh?

It's not huge, about the size of a large watermelon. It's heavy though, I haven't weighed one, but it's gotta be upwards of 80 pounds.

I have the 05 sports package and it comes with vlsd.

like mr pharmd said.
it comes with vlsd only if you get the package.

Cool, just make sure that the pumpkin that you are getting is LSD. Some of the 350Zs are available without them.

Guys - I have 3.92's going in right now. I'll report in a day or two after my findings. The 3.3 to 3.5 upgrade isn't worth the money - buy a torque converter if that's how you want to go and keep costs down if the dough isn't there - $450.

Doing it right - isn't cheap. Go with the 3.9's if anything. The cost of this is about $1700 in parts. 6MT diff and ring and pinion set. You still have the VLSD, unless you buy the Nismo diff - add about $300. You also need to have the shims - if not - your throwing away the money on noise and breaking gears soon.

Rick

Cool, definitely let us know how it goes. My biggest concern is ruining the car for the highway, but I'm sure that it'll be great at the drag strip with a 3.9. Man, I want to get it done now.

damn the 3.9 final drive sounds insane but like roneski mentioned the hiway and the mpg would be a bitch for daily driving.

I think the 3.5 final drive is okay compare to changing the tq converter bc it's still replacing oem parts with one another. I have heard level ten's tq converter breaking and that is just not cutting it for me.

I am very interested in your sig about Nismo CAMS. Do they really work if my head is not ported and how is the idle?