Determining differential type

[Turbo67camaro]

I had a 12 bolt rear built about 10 to 15 years ago, and I can't remember what differential was installed, nor can I find the paperwork. If I recall, it was done by Pro Gear in San Diego.

If I were to take off the cover, and posted a picture here of the guts inside, would anyone here be able to tell what type of differential was installed (i.e. GM, Eaton, Auburn, etc.).

Hopefully, this isn't a dumb question, but I know very little about rear ends.

I'm trying to get an idea if it will be able to handle about 550 to 575 hp.

Originally, I was going to aim for 450 hp, but I'm going to fork up some extra cash to upgrade my fuel injection system and turbo / boost level.

I do remember having it straightened and the center section was welded to the tubes, but other than that, all I remember was using 3.42 gears.

Maybe I'll get lucky and Pro Gear will still have records of that work. I just sent them an email, but I'm not optimistic they'll have records going that far back.

[chicane67]

Huh... lets see... 10 or 15 years ago. That means that I most likely did the work. Post a picture of the car... Ill probably remember it from sight.

It was probably me that recommended the 3.42's as well... so I can pretty much guarantee that it has an Eaton in it too.

And yes... Mark should still have your invoice in the system.

[Turbo67camaro]

The car was in pieces at the time.

I bought the rear from a guy in New York, and had Pro Gear finish it as a bench job.

It was powder coated red if that helps.

My wife and I picked it up in a blue Ford Ranger. At pickup time, it had to be taken off the pallet because the pallet wouldn't fit between the trucks wheel wells. She remembers this part not me :banghead: .

We bought a new truck in the winter of '97, so it had to be before then.

What I can't remember is what internal parts were supplied from the guy from NY, and what parts were from Pro Gear.

If you remember what you did to the internals, I'm envious ! Wait till you get to my age when brain seepage commences :eek: .

No worries. If the invoice is still in the system, that might get 'er done.

Mike

[chicane67]

Ahhh... a bench job. They were all a blurr. After buliding some where around 10k differentials... I understand brain seepage. But... getting the tubes welded and then having the housing powdercoated... would be a stand out process.

Although... if you take a picture and post it... I can tell you exactly whats in it with realitive ease. And it might just spark a memory of what I did... as it will show if I did my normal gear prep and simple modifications for performance use. Make sure you get the ring gear stamped number in one shot... because I can track it that way too. I actually kept track of pinion depth numbers back then to track any changes in R&P manufacturing and/or if there were any housing irregularities that influenced specific gear wipe patterns.

[Turbo67camaro]

Before I crack the cover, I'll try calling Pro Gear and see if they have the details. If not, I'll crack the cover and post the pics.

Thanks !