Impalas.net banner

1 - 10 of 10 Posts

·
Super Moderator
Joined
·
13,049 Posts
Welcome to the Team James!

I don't see a big "P" on the case of the differential. It is that case that is unique and only that case contains a limited slip rear end. If you have everything as you say go to a Corvette board and look for a rich doctor or lawyer who is restoring a 1953''62 Corvette. They are the ones who are paying through the nose for original limited slip rear ends because even back in the sixties very few cars ('vettes included) had a posi. They were only sold up north to traveling salesmen who drove Belairs and Biscaynes in the snow that ordered a limited slip rear end from the factory. Most of those cars rusted away from salted roads which makes a posi a rare find today.

Big Dave
 

·
Registered
Joined
·
24 Posts
Discussion Starter #3
Welcome to the Team James!

I don't see a big "P" on the case of the differential. It is that case that is unique and only that case contains a limited slip rear end. If you have everything as you say go to a Corvette board and look for a rich doctor or lawyer who is restoring a 1953''62 Corvette. They are the ones who are paying through the nose for original limited slip rear ends because even back in the sixties very few cars ('vettes included) had a posi. They were only sold up north to traveling salesmen who drove Belairs and Biscaynes in the snow that ordered a limited slip rear end from the factory. Most of those cars rusted away from salted roads which makes a posi a rare find today.

Big Dave
Thanks Dave. Yes I think it has the thin P as opposed to the thick P. The main caps are stamped with a punch and the case has the corresponding punch marks. That would make be believe that the maybe the posi came from that case; but who knows for sure. Are you saying that all the posi units came in cases with the thick P. I believe that the thick or thin P determined which plant produced the case. Was the final axel assembly also at the same corresponding Plants. And are you saying only one plant produced axels assembly with posi units?
 

Attachments

·
Registered
Joined
·
956 Posts
There were 2 different "P"s, but they would be located on the side that we can't see in the picture.
 

·
Registered
Joined
·
24 Posts
Discussion Starter #5
There were 2 different "P"s, but they would be located on the side that we can't see in the picture.
Yes I know the P is not visiable, just didn’t feel like going out to the garage to take a photo. Here is one..so what’s it worth? The caps are marked with a punch for correct location? I think this is the thin P.
 

Attachments

·
Registered
Joined
·
956 Posts
Yes, it is the Thinner P. That and along with the Date Code Numbers tells us that it is made by Detroit.

I'm only here for contributing info now and then, I'm not really up on current prices, especially one all apart.

If no one jumps in, I would recommend watching E-bay. It's a great place to get an idea on current market prices.
 

·
Registered
Joined
·
24 Posts
Discussion Starter #7
I see a few on E-bay and some posted here for $750. Anywhere from $500 to what some guys think they have is special to a corvette those are up to the $1200 range. I see just the outer housing for up to $350; but again a earlier housing so they think it would go in a corvette. I think if I had a impala or belair, etc to go in I would pay around $400. But that just me. If the clutches were good then I could work on it myself and have a posi for $500.
 

·
Super Moderator
Joined
·
13,049 Posts
Corvette was always a road car not oriented to drag racing so few had a posi rear end as that affects how a car handles in turns. With a the advent of IRS in 1963 that pretty well sealed the deal on drag racing as the IRS didn't appreciate hard launches. So very few Corvettes had a posi when new. The limited slip rear end was mostly installed in big cars with a trunk full of product that a traveling salesman pedaled from town to town in all weather. That car needed a posi to negotiate dirt roads or snow. That is why most posi units were in a full size. Not for drag racing, as they were too weak for that (I blew one up a week behind my 409), but to cut down on wrecker calls to get unstuck and back on a paved road. Early limited slips are useless as they had a coarse spline on their pinion (17 splines) compared to 1963 and up 26 spline yokes which can transmit more torque.

This was because the Chevy was the last car in GM 's fleet to get a V8. Prior to 1955 the biggest baddest engine you could find was a 235 six (three main caps and drip oiling unless it had an PowerGlide, then you got an oil pump). The 235 was Chevrolets answer to the Hudson, the Ford flat head, and every other company that made cars with bigger more powerful engine (it was in production from 1929 to 1962). Without any power there was no need to make things like the Borg Warner transmission or the rear end any stronger. The 265 V8 SBC introduced in 1955, and the all powerful 283 introduced in 1957 began breaking parts as fast as you dropped the hammer on a hard launch. That is why the posi was modified in 1963 (with the introduction of the 327) to make it a bit stronger.

There isn't a drop out ten bolt early Chevy (1939-'64) rear end that can withstand modern SBC power never mind the axle twisting torque of a big block (includes the 348 and the 409). Hence every one wants a Ford style nine inch (1957-'86) rear end made by the aftermarket since the Ford rears are no stronger than a Spicer ten bolt from 1965. Spicer 12 bolts and the Dana 60 is what most people that don't have the power sucking nine inch use to replace the weaker six cylinder power train from before the eara of muscle cars (1965-'71).

A restorer looking to make a white glove clone of a car he isn't old enough to remember will pay for that posi for his 1958-'63 'vette. Even though they rarely if ever had a posi from the factory. He wants it because every one knows it has to have one, even though with any size tire and a modern power plant he will break it. I had a 1958 'vette that I rebuilt and all of the parts for the suspension except the rear passenger side radius traction bar were off of a full size Chevy. No stronger, no better.

Big Dave
 

·
Registered
Joined
·
24 Posts
Discussion Starter #9
Lots of information Dave, thanks. So I gather those E-bay prices are not realistic. At least this is a 64 unit so should be the stronger of the two. A friend who is in my chevelle club with me is building a clone 409. I doubt he will take it to the track or beat on it to much. I guess he would just like a posi. Another friend and former colleague who does tons of favors for me has this unit that he would like me to sell for him. So all things considered what would be a fair price. Just so happens the two guys live in different communities. I would like them to both be happy. If you would, could you send me a PM with what you think is a reasonable price. Thanks again.
 

·
Super Moderator
Joined
·
13,049 Posts
Craig's list and flea-Bay are your freind for a current value. Also where you live makes a difference.

A friend of mine sold a complete P case posi to a Dr for his 'vette and paid him $1,200 for it.

I sold two that I owned and used in my '53 Chevy for $100 each back in 1969 (I had them in my '53 150 2dr sdn powered by a 409 and I broke one a week on the street with seven inch recapped slicks from M&H. I used to carry tools and a cheep floor jack in the trunk with a spare P case posi sitting in the spare tire well to prevent being stranded on the road. I eventually pulled the Chevy rear end and installed a '64 Olds rear in it's place and then started breaking Borg-Warner T-10 transmissions.

Big Dave
 
1 - 10 of 10 Posts
Top