What do you need to change your rear end gears and make my car posi (will I just need a new rear end completely)? Just the ring and pinion? I'm new to swaping gears, but I think the rear end in my car is fine now, I'm only building a 200rwhp car, so I won't need like a 12 bolt or anything. I want to put 3.73's in. So you just swap the 2.73 ring and pinion in there now or what? Is it that easy? What else do I need to do, this car needs to be woken up!

What RPM am I going to be running at at 60 mph?

 

If you are asking what you need to do to make the swap best bet is to take it somewhere and pay to have it done. If you havent done it before or are not mechanicly inclined you shouldnt try it. Also is your car a posi now or a one legger ?

 

The 2.73 fits a 2 series differential. You will need a 3 series differential for the 3.73 gears. You will need a new 3 series Eaton posi, 3.73 gears and a good installation kit. You also need someone who knows how to set the pinion depth, bearing preload and backlash to get the correct contact pattern.

 

You can get 3.73 in a 2 series also.

 

All this is covered in the 10-bolt sticky at the top of the page.

JamesC

 

I am pretty new to actually working on cars... I come from a family that can't even change their own oil!!! But I love cars and really want to learn how to build them, so I'm at a big disadvantage. I'll pay for someone to do this... I don't want to mess it up. Labor costs??? Anyone have a ball park guess???

 

What's the difference between the 3 series 3.73 and the 2 series 3.73? My car DOES NOT have posi now... only one skidmark =(

 

Get these

http://store.summitracing.com/partde...5&autoview=sku

http://store.summitracing.com/partde...5&autoview=sku

http://store.summitracing.com/partde...5&autoview=sku

and about another 200-300 dollars in labor and your set.

 

the 2 series is a "thicker" gear set

 

Lol... by thicker you mean more durable? I just want which ever gear will wake up my car more and not break on me. Any one know how badly my gas mileage will be effected? I get 27mpg now... maybe like 22mpg with 3.73's?

 

Thicker meaning wider to compensate for the 2 series carrier. And actually since all you have is a 305 you mighty wanna look into a 3.42. And if your want to save money and not buy everything new you can always go to a junkyard and pickup another rearend with a posi and better gears and just swap it in your car. The MPG thing is ok long as you keep your foot out of it but there is a drop when increasing gear.

 

It will spin the "tire" pretty good even with 2.73's... I'm thinking with a 3.73, it would probably roast first, and chirp second. You personally recommend the lower of the two? How much of a difference between them?

 

I recommended the 3 series Eaton because he was going to need to swap the differetnial anyway. The '92 will need a 28 spline unit.

Here is the difference between series. These are from the 12 bolt. The one in front is a 2 series, the second one is a 3 series and the one in the rear is a 4 series. Notice that the only difference between them is the location of the ring gear flange.

 

Thanks for the pic, I can see the diffence there... This is going to be expensive... about $1,000!!!

 

Just a thought, you might also consider just buying a complete used Camaro rear end with the gears and posi-trac already installed (might even be able to up-grade to a nine bolt and/or add the stock rear wheel disc brake option at the same time).

Although there is always some risk associated with buying something like this used, this would be a way to get your “hands dirty”. Even a novice wrench turner should be able to do this work himself on a weekend. I also suspect it would be significantly cheaper.

 

Dosent need to swap anything with the powertrax unit it takes place of the spider gears. He uses the same carrier the thick 3.73 2 series gears and the powertrax unit and he is done. The stock axles work fine with the carrier he has.

 

The Eaton posi is $420, the gears are about $165 and the installation kit is about $100. Labor should be around $200 to $400. I can fix you up with a very good rebuilt 9 bolt with 3.27 gears and a Borg Warner posi for $550. It needs disc brakes.

 

Do I need to replace the whole rear axle too? The brakes? Everything?

 

If you get the Eaton and the gears then those will go in the rear end that you already have. If you are interested in the 9 bolt then it will replace the whole rear end. You can upgrade to disc brakes with the 9 bolt.

 

So I can still use my stock rear end? I'd like to keep that in there, save money because my brakes (even though they are stock) work excellent. They feel more firm than my friends new performance brakes on his LS1!!!

 

My guess is that you haven't read the sticky.

JamesC

 

Yea, it would be a good idea to read this. https://www.thirdgen.org/forums/tran...-10-bolts.html