7.5 rear end 28 spline upgrades with new parts?

[565bbchevy]

So my 86' Regal which is just a cruiser still has the factory 7.5 with a 200R4 and the stock rear gear and I would like to upgrade it using a new 28 spline posi carrier and new axles and I want a 323 gear, the engine is a mild SBC putting out about 350 horse.
So I am looking for recommendations for the new posi carrier (considering Auburn) and axles which I am not sure on what length I would need.
I am also not looking for junkyard parts or swapping in another rear I am just considering this over installing the rusty, neglected 373 open Monte SS rear end I have here.

 

[64nailhead]

The axle lengths for a 26 vs 28 spline will be the same - the same lock pin diameter means the same axle length. You're going to have to order a set of axles if you don't want to fabricate something. The only direct fit axle I know of is a 2WD S10 stock axles. They are very close in length, 1/4-5/16" longer and will require a spacer between the brake backing plate and axle flange.

As far as carrier, I'd recommend any name brand clutch style posit - I would NOT recommend an Auburn, but an Eaton or Yukon (both of which are rebuildable) is what I'd be after.

 

[565bbchevy]

You're going to have to order a set of axles if you don't want to fabricate something.

I thought Moser had some direct fit axles but it might be 26 spline.

 

[pagrunt]

I thought Moser had some direct fit axles but it might be 26 spline.

Both in 26 & 28 spline, in both inch & metric studs.

1978-1981 G-Body - Moser Engineering

www.moserengineering.com

1982-1987 G-Body - Moser Engineering

www.moserengineering.com

 

[565bbchevy]

Both in 26 & 28 spline, in both inch & metric studs.

1978-1981 G-Body - Moser Engineering

www.moserengineering.com

1982-1987 G-Body - Moser Engineering

www.moserengineering.com

I am wondering what the difference between the two.

 

[64nailhead]

I am wondering what the difference between the two are, metric vs standard studs?

You can get whatever knurl size, thread size, center drum or rotor diameter, bolt pattern, length, spline length, c-clip or non c-clip, etc.

I've ordered 2 sets from Moser and they make them to whatever you order. You can usually get a discounted price ordering them from someone like Quick's if you order a bearing kit, gears, diff, etc. at the same time. They get a better price and pass along a portion of that if you buy multiple products. Quick's and Moser are worth a call if you plan to go this route. I bought one set from Moser direct, since then I've bought everything from Quicks.

 

[565bbchevy]

You can get whatever knurl size, thread size, center drum or rotor diameter, bolt pattern, length, spline length, c-clip or non c-clip, etc.

They were both listed as 1/2" studs so I edited my question.

 

[79 USA 1]

Check Tom's Differentials. I purchased a Detroit Locker and 28 spline KA brand axles from him years back.
His prices on LSD's were less then Jegs or Summit as were the price on the axles.
Really good people to work with when I had questions about what I was looking to purchase.

https://tomsdifferentials.com/

 

[64nailhead]

They were both listed as 1/2" studs so I edited my question.

Missed that.

I still recommend calling them. It's been a while since I contacted them, so perhaps Covid BS has slowed down their customer service abilities, but when I did contact them several years ago, they were asking questions that I never expected. And both times they were willing to explain the reason for the questions, how to measure, etc. It's very nice to contact someone that is truly knowledgeable of the product they are selling.

 

[carnutjw]

Just received a Summit order today, just happened to have these-

The 78-81's have 1/2"-20 thread and .453" hole for 7/16" studs, 82-87's have 1/2"-20 and .484 hole for 12mm studs. Not sure what differential I will use. I have junkyard find '97 T/A 2.73 posi(Auburn style), but would rather have a '98-02 F-body Torsen style, 3.42 gear and 200-4R. BTW- Moser's stock photo on their website does not show the dual drilled(tapped) pattern.