neekos

I am about to buy 3.07 Gears from someone and need input. It is going into a 94 LT1 which currently has 2.59 gears. A couple of questions. Eckler's has a rebuild kit for the rear which I believe is around $ 140. In addition to that price, how much should a shop charge me for installing the gears with the kit I will supply them ?

Also, what sort of improvement will I see.

TIMSPEED

With an LT1 Automatic, I'd go with a 3.75 or 3.73 set of cogs, they'll give you the best performance for the price.
A shop would probably charge around $500 to install a set of gears.

Springer's LT4

I have the 3.07's in my LT-1... and while it's a great improvment over 2.59's, the car would respond better to 3.54's or 3.73's... If your paying to change them out... I'd personally go 3.54's unless you drag race often. Then 3.73's might suit you better.

vader86

I would go 3.54s for an auto, but you will feel a bit faster off the line with the 3.07s

CFI-EFI

TIMSPEED,

He is already committed to the 3.07's.

neekos,

As a ball park figure, I agree with TIMSPEED, $500.00 ought to be about right. That is with them doing the R&R on the diff. You could save some money if you are willing and able to remove the diff yourself. I would hold off on buying a rebuild/installation kit until you have selected an installer and discussed with him, his feelings on you supplying NEW parts. Shops generally make a profit on the parts they sell. Some shops will refuse to do a job if they don't supply the parts. I suggest that you have an understading with the shop, before you commit your resources to parts you may not be able to use.

Just so you are aware, the diff case, that's the case inside the differential assembly that the ring gear bolts to, has to be changed when going from 2.59 to 3.07. Possibly that is in the Eckler's kit you mentioned. While it's all apart, make sure they inspect and replace any questionable bearings. Posi clutches, as well. As a final note, there is no better time to replace the speedo gears, if that operation is applicable to a '94. Have fun! You'll love it!

GlockLT4

Cogs .. hehehe :jester :hat

Goody

A diff to diff swap isn't difficult at all. Mostly straight forward mechanical stuff. So the $500 sounds good. You are better off with the 3.45 to 3.73 choice though......just do it and enjoy it. :seeya

neekos

Quote:
Just so you are aware, the diff case, that's the case inside the differential assembly that the ring gear bolts to, has to be changed when going from 2.59 to 3.07.
___________________________

I am starting to think that the 3.54's are the way to go. Luckily I have not finalized anything yet. What would a new carrier cost me ? and is this true that I need a new carrier ? I am getting conflicting reports from people.

Thanks again guys..


[Modified by neekos, 7:42 PM 2/22/2002]

CFI-EFI

3.45 gears would be MY choice, also. I didn't realize that ratio was still optional. Only you know what YOU are using the car for, and what YOU like. Measure your tires and get the old calculator out. Check cruise rpms (if you spend any time on the highway) with different gears. With a little analysis, you can decide what the best gears are for YOU. What I (or anyone else) likes may not be suitable for YOU. The lower (higher numerically) you go, the quicker the acceleration, AND the higher the cruise rpms.

For Dana (stock Chevy) gears a case change IS necessary. Some after market companies make a "thick" gear that allows the low ratio gears to work on the "fast" (high ratio) case. I cannot advise you as to what is available in your chosen ratio for your axle model. At least you now know that it is likely, and can ask as you shop for gears.

emoshn

I've been considering going to a 3.54 ratio also. I currently have a 92 auto, so am assuming I have a dana 36. Also my codes are G92/GU2. I believe that means I have a performance axle ratio 2.73.

If I'm correct, would I be better off changing out the entire differential myself, saving labor, or take it to a shop for a ring/pinion swap?

bellmd

Just put a set of 3.54's in my 1994 LT1 auto, VERY HAPPY with them! I too had the 2.59 gears and my total cost to have the whole thing done was $1050 with them doing everything, I went with a very reputable shop here in the Houston area because I've seen so many things go bad with differentials in my limited experience. I'm sure there are ways to save on that price if you have experience or know the right people!

We discussed the 3.73's at length and finally settled on the 3.54's for the auto, not sure how you would have liked that ratio but I can say I'm smiling alot these days with the 3.54's :yesnod:

RadPolo96

I would have to agree with what TIMSPEED said about the gears and the price. :cheers:

CFI-EFI

First, If your car is unmolested, the diff should be as you suspect. Which method would be the more economical would depend on what you end up having to pay for the diff you want. Even if you were to have a shop set up a new ring and pinion, you can still save money doing the differential R&R yourself. Good Luck.

Zora

Beware of going over 3.07 gears in a Dana 36.....if you plan on seeing some track time. Croozn a good friend of mine on the forum has broking 3 Dana 36 (3.54) rears. :cry And all of came from different shops. :eek:
I would change to the Dana 44 before going higher than 3.07. :yesnod:

TNTC4VETTE

OK, I'm gonna stick my nose in here...I remember a post from JD90383 where he had discussed even going BACK to 3.07's due to traction difficulties with his monster motor...if you're going to stay with a relatively docile setup, then the gears will certainly benefit you...however, if you go nutzo on a big displacement or power adder frenzy, a milder gear my be the way to go, so you (pardon the pun) don't lose your **** in a race. Anyhow, I'm currently in the same boat...but my choice'll probably be a mild gear and a Dana44...for what it's worth, seeing as I'll never get rid of this car despit my many attempts (that's what I tell my wife)

SLOWBUSA

Will the Ikerd's heavy duty cover eliminate the Dana 36 problem? It supports the 2 bearing caps like the Dana 44. CROOZN has one of these installed and recommended I do the same if I do a gear swap. Would like to get a complete differential like the one advertised in the forum with the 3.54 gears. :confused:

jpee

It all depends on what you plan on doing with your car.. If you are going to do 99% street driving, & just take it to the drag strip once in a while the Dana 36 will be ok...especially if you are NOT going to use Drag Radials..

A Dana 36 will usually hold up if your 60' times are in the 1.80 or slower range..

However if you plan on going to the drag strip & using DRAG RADIALS, & a high stall converter (2600-2800) then go with a Dana 44..

If you are planning on leaving your stock converter & not use drag radials, save some $$ & stay with the Dana 36..

Mackey had a Dana 36 & put in 3.73s & raced it for 3 years with no problems.. on the other hand I had the EXACT same thing Dana 36 with 3.73, & a Vigilante 2800 converter, & broke my rear in 9 months... just luck of the draw I guess...

bottom line it really depends on what converter, tires, & how much drag racing you plan on doing..

Bradley3

I have a dana 36 rear and I'm going to change out to 3.54 gears. I push my car pretty hard and times, but I never go to the track and I WON'T be changing my converter... so I'm sticking with changing just the ring and pinion.

Zora

You are right Croozn does have the Ikerd HD cover now.....but it has not been tested yet:nonod:. He now has 3.73 gears. :yesnod: