I have a 1983 Z28 and I've recently discovered that I've got a 7.5" peg legger. I have just installed a 355, and want to put this power to the road.

So naturally I need a "Posi" (Limited Slip) carrier equipped with 3.23 OR HIGHER gears.... that will accomodate my axels.

What I really need to know is what year and make of cars/trucks/vans came with this. I just got back from an unsuccessful trip to the bone yard where I jacked 4 vans out of the mud, and popped the covers only to discover that they were all open difs.

Also did 4x4 blazers come with "posi"? I have a 4x4 blazer jacked out of the mud, but I'm not going to bother with the rusted bolts unless someone tells me it's posi.

thanx!

 

i dunno if this is gonna help but when i called a bone yard and they ran the #'s off my rear end (which is 3.08 posi) they said it was giving them refference to an S-10 pickup. I'm assuming that they used some of the same rears that camaro's did. But thats still a 2 series carrier i think so all that ive just said may be in vain....oh well

Brandon

 

The only usefull thing your going to get from a junk yard would be a lower "higher number" ring & pinion. The little S10's like mentioned have them also 80's Jeep Wagoner's "2.5L, 4/5 speeds have 3.73's" also 80's-90's Safari/Astro vans have them also. Intresting thing I seen a few days ago in the bone yard was an 80's Monte or Regal but it had a 7.5, 10 bolt rear also and alot of those cars were posi.

 

Why can't I use a posi carrier out of an S-10?

 

He wasn't saying you can't use it, just that they typically weren't posi. But, if you find a 3.73 open rear, for instance, you could use that set in your car, then add the posi (such as a PowerTrax).

Posi rears typically had a metal tag under one of the cover bolts identifying it as such. Sometimes those don't go back on if the cover has been removed, but if you see the tag, it's most likely a posi.

Also, don't forget that '89-later went to 28-spline (at least, I assume that carried over to the other 7.625" 10-bolt series). What I have never heard is if the S-10/Blazer/Astro axles are the same length as our 3rd gens, such that finding a posi carrier from one of them would also provide the required axles.

 

I personally havent seen an S10/S15 with a stock posi traction system. You could get one from an AWD Safari or Astro van. As far as fitting the new axles in they may or may not work. When I went to 3.73's in my old Camaro my Dad said the axles from the S10 wouldent work. I never asked why but either the wheel bolt pattern is truck only or the axle shafts are smaller or bigger.

 

Thanx for the info guys. I have located an AWD Safari... I will bust it open.

As for the axels.... why can't I use the axels I have now?

Last Question: Wouldn't a 4x4 blazer have posi? Or is it really 3 wheel drive?

 

The carrier may be different but I and Im sure a few others would love to hear otherwise.

 

Your '83 rear has 26-spline axles. In '88/'89, they went to 28-spline axles. If you get a carrier from a vehicle newer than that, your axles won't go into that carrier.

Astros have 5-lug wheels. I'm assuming it's the standard Chevy pattern, but don't know for sure. I wouldn't be surprised if they are different length than 3rd gen, or have some other detail difference, though.

4x4's don't have posi in the front diff. Steering would get very "interesting". Many never had posi in the rear, because the extra traction provided from the front drive made it unnecessary.

 

one friend had a 4x4 blazer with 3.73, or 3.42 and posi from the factory it was an 84, had an auto and 2.8l

another friend has a 89 blazer, 4.3l, 4x4, it has 3.42 and posi out back, i believe it is a highcountry package or something like that

 

I had a S-10 posi unit in my garage. I gave it away. I would not use it in a high-power application. It is the Eaton Gov-Lock unit, which uses a pair of weights as a sort of governor to apply the clutches.

What I would suggest, is to go to the boneyard and get the whole rear out of a 90-92 6-cylinder 5-speed car. This will have 28-spline axles and a 3.42 gear. Then get the SLP posi and bolt it in. If you do it that way, you dodge the whole gear setup issue, get the better posi, and get the better axles.