I plan on doing an L98 swap soon, and after that I would want to upgrade from 2.73s to 3.73. I hate my limited slip and obviously would want to keep disc brakes. I havent found a new rear end yet so this is really just me being interested now. Im really a noob so I know its probably been asked a thousand times before but im interested in what the cost of this swap would be if I didn't do it myself, or if I was to do it myself what exactly would I need? Also are there any hidden costs i should be prepared for? I know my speedo wont work but really that's something id be prepared to live with for a short period of time. Thanks in advance for any advice

If you are just swapping out the axle for another one with the gears you want..then it's an easy/cheap swap. Some brake fluid would be about the only supplys you'd need. But it'd be a good idea to change the gear oil and check the u-joints while you have everything appart.

If you plan on putting new gears into your axle, then that requires special tools. Mainly a way to measure backlash and other specs inside the center. A gear swap like this isn't physicly hard, just not something recomended for the home mechanic. If not set up properly the gears will whine and could possibly fail early.

Im probably just looking for a complete axle swap, but its whatever I could afford/do

A new Eaton Posi is $440, a set of gears is $175, the installation kit is $98 and labor could run from $200 to $500. A Duragrip posi is $360, so that could save you a little. I wouldn't use an Auburn. A new Moser 12 bolt is about $2220 with the Eaton Posi and c clip axles. Finding a good used rear end with the gears that you want and a good posi might be hard, but it's possible.

So you have a RS with a 2:73 open rear and you hate the LIMITED SLIP.. You want to do Two wheel burnouts, correct.

Yes - I think the OP is confused. Limited Slip IS a posi unit - which is what you want for a street car - it means both wheels turn, but that one wheel will "slip" on a limited basis if necessary - mainly for hard cornering where the outside wheel HAS to travel at a slower rate than the inside wheel.

I think the OP means he hates the fact that he does NOT has limited slip, as in no posi unit, as in only one wheel gets power, which is pass wheel.

If you can deal with the wheels sticking out 1.5 inches farther out on each side in the rear, and you have (or can get) the 16" rims, consider a 4th gen complete rear swap - a complete rear can be had for under $400, it swaps right in with little issue (ebrake is only real issue), and if 1998+ will have Zexel-Torsen posi, easy to get with 3.42 gears, and has nice LS1 rear disc brakes! Just get one with the ebrake cables still attached - makes connecting to your ebrake cable much easier. I'm really pleased with my 4th gen 3.42 geared posi LS1 disc rear, and the swap only took me a couple hours.

Personally, I would not add 3.73s unless you had a manual trans. The L-98 is a low rpm TQ monster and does not require more than 3.23-3.42 gears. 1 tenth was gained going to 3.73s from 3.23s huge waste of money. Now if you add a cam,heads stall and intake the 3.73s will of course help then you will ditch the TPI for a better flowing intake.......

After reading allot of threads and hearing nothing but good things about the Eaton posi. for a street/strip car, and after conferring with a Rear End shop with over 20 years of experience, this is the way I decided to go.
Here are some photos of my 10 bolt upgrade including a Eaton 28 spline posi, new 28 spline axles ,3.42 ring and pinion and LPW Ultimate support cover. For my application its perfect and I second the 3.42s
Heres a link to Eaton = http://www.eaton.com/EatonCom/Produc...iLSD/index.htm
And heres one to LPW = http://www.lpwracing.com/Diff_Cover_...omparison.html

Actually I know the difference, I just made a typo lol. My bad that makes me feel like an idiot now... so yeah what I meant to say is I hate my open diff. But I have have have 17'' rims and my e brake doesn't exactly work so I guess a forth gen swap would be just fine, thanks for the imput guys my bad on the typo, I do know the difference just made a little mistake.

I would not go with more than a 342. You will be out of your powerband with 373's too. You could always just find a 4th gen rear at a junkyard. Cheapest and easiest way.

I would rather go to my local junkyard and spend $100-150 for a complete rear!