So one of this winters projects is to add some gear to my rear to take advantage of my new 355 HSR's cam and converter.

Specs:

Lunati Cam

Hydraulic, fair idle. Needs 3200-3500 RPM stall converter, headers and 4.10 gearing or better. Good for EFI bracket race car. Excellent increase in torque and horsepower in mid to upper RPM.
Advertised Duration (Int/Exh): 285/295
Duration @ .050 (Int/Exh): 235/245
Gross Valve Lift (Int/Exh): .507/.534
LSA/ICL: 112/108
Valve Lash (Int/Exh): Hyd/Hyd
RPM Range: 3200-6500

Edge 3200 10' stall 700r4 w/ lockup. Feels real good. Tranny has stock gears but corvette servo, improved clutches, shift kit. Megashifter.


I picked up a used rear-end today from a 92 RS so hopefully it has the 28-spline axles. I'll be taking it apart to check in the next couple days. Came with aluminum cover and gm 373's. Its a 3-series carrier w/ a gov lock. I will not be using this but it is for sale.













My current rear end is a low mileage 3-series w/ stock 323's and a POSI.










My first question is ( and I already know the answer to this, Auburn, ) what type of carrier is this? I ask this because the pictures I've found on heare and elswhere show a case with an angled top and mine has a straight edge like an Eaton. What gives? (see attachment below) And if you notice mine do not have yellow springs.

My next question is I also have a wrecked 2000 S-10 pickup in my backyard and from what I've read , it should have 410's in the rear based on the fact that it is a 4-cyl auto 2wd. Since I have both 373's and 410's I am torn as to which would be a good fit for my setup. I understand that Lunati says to go with the bigger gear but the 700r4 begs to differ wouldn't you say. Then on the other hand the HSR will pull to 6500 rpm's

I don't know what to do please help someone


Thanks

 

The older Auburns were cylindrical, like the one you have. Since it has so few springs in there, it's probably a stock one; not a "high-perf" one.

I think 4.10s are too much for a car with a 700. 1st is too low. Might be OK if you got the aftermarket set with the different ratio but I'm guessing that's beyond the scope of this project.

IMP you'll be happiest with the Auburn carrier, whether it still works or not, and the 3.73s. If the Auburn is 26-spline and the other is 28-spline, you can sell the 28-spline axles and recoup some cash.

 

Yes I was thinking that between the axles, spacers, gears, and carrier I could make out with the cover for free and then some. 373's were my gut instinct as well. Glad to hear I have one vote for leaving the 410's right where they are. It's cold outside. BRRRRRrr!!! I know the Auburn works great because I've been using it right up until 2 weeks ago when I began the teardown. When I say low mileage I mean 17,800 total.

Thanks

 

It's an Auburn and it will have 5 springs in it. Is it 26 or 28 spline? If it's 26 spline it's not going to work with the 28 spline axles.

I'd stay with the 3.73.

 

Yes its original to the car. 87. So its got to be 26 spline. I will in the short term just keep that with the stock axles and change over the gears and the cover. Aleady $150 cheaper than if I had to by both online (summit). Maybe if I keep the axles for a bit and come across a good deal on a Torsen then I will upgrade.