do you realize how lil difference there is between the two? Get the 4.08s

 

yea...he charged my buddy 200 for installing a quaife lsd
150 for my headers,as i mentioned earlier 200 for my previous 3.9fd
but i hope he doesnt mess up anything though.
wish me luck still!

 

so why do 3.9s cost so much more then the 4.08s.

Also is there any drawbacks to having gears that may put stress on surrounding stock parts.??

 

because they are different parts -just like a clutch for one year Z and a clutch from another year Z can be different

there is no added or reduced stress with one set of gears vs another

 

Plus, i believe Z1 ^ told me a while back that the 3.9's were much less of a seller and usually had to be ordered and take a while, while they usually have the 4.08's in stock. Correct me if im wrong Adam.

Also that most people opt for the 4.08's...because...why not? They are better and cheaper.

For Automatics, however, i would opt for 3.9 or 3.5 since we have only 5 gears and 4.08 would be alittle too much for streetability.

 

is there a recommonded type of diff fluid you use for aftermarket gears.

i was thinking about getting SPL pro differential mount bushing.. would that be a good upgrade while getting gears.

 

ive had the 4.08 installed for about a year and i love them. With the Vortech and FD gears my car rips

 

I've heard people talk about adding a thicker fluid, but ive also heard it doesnt do anything to help. I know there is a very important time frame to when you get installed to when you must add new (even if same) fluid, but i cant recall how many miles that is.

I believe just running the same fluid would be more than adequate, but i could be wrong.

 

The quaife LSD and the FD have two different break in periods. Your susposed to change the fluids on the Quiafe after the first 500mi, don't do what I did and wait 3000, it'll look and flow out like mud. I think the FD is basically go easy for the first 500-1000mi before WOT load... that was damn near impossible for me.

If you're going to put the diff bushings in definately get it done while the diff is down getting the gears & lsd in, no need to drop the diff twice.

Fluid brand is personal pref, but most quality 75-90 or 90sae gear lube will work. I like Motul as a brand for fluids but it's priced out like liquid gold.

 

the problem is that i have no vdc and no traction control. so do i still have a lsd? if so would it be ok if i left the stock one in there because i was only planning on doing the gears.

 

You have a base model?

 

If it is a Base I highly recommend getting a better Diff. Your already in there installing the gears mise well do the diff at the sametime!

Thats what I figured. Will be having my Quaife Diff, Nismo finned diff cover and gears installed on the 26th! Looking forward to it Can't wait.

Shop around! You can pickup the 4.08 Gears alot cheaper.

 

no special fluid is required, it will take whatever you would normally use

the SPL rear bushing set is a very worthwhile upgrade, and more easily installed since the pumpkin will be out of the car already

 

yea money is kinda tight.. so idk if i can efford gears and a lsd.. would there be a problem if i just got the gears? or should i just wait to get everything

 

^ i would wait or doing it twice will make money even tighter. lol

 

Funny, I see those "features" as being the problem.. but that's like the fluids you run, it comes down to preference.

+1 for rocking the base.

 

Its the same Labor to swap out the Diff and gears together.

Otherwise, You'll be paying twice as much in LABOR! Your choice. Me personally, I'd save up and do it all together. Thats the route I am taking.

 

Its only a problem if your running the stock LSD....which sucks.

If you upgrade to say the Nismo or Quaife...then add the 4.08, you'll be good to go brotha.

 

is it worth all that money for gears and lsd... rather then buying more bolt-ons?

what are some of the best lsd that would work well with the 4.08 gears..?

 

With 4.08 Gears your going to want good traction and hook-up! If your planning on more performance Mods then I say yes. Don't do it half assed. Tackle & upgrade each project correctly...

That would be like getting a Vasectomy and only tying off one Nut! Then wondering how tha B*tch got prego