All 9C1's posi?

I am in the search for a posi rear end for my car. I went to a local wrecker and they had a 94 Caprice 9C1 cop car package. I checked the spid on the trunk lid and couldn't find the G80 code. It had GU4 which is the 3.08 gearing. I was checking out on the net and what not, but I was under the impression that all 9C1's came with posi. The spid also has 9C1, LT1, and a bunch of the codes that indicated it was a cop car such as cooling for the oil and ps. So I wanted the diff cover pulled to check for any metal and to see if it is a posi or not. They called me back and said that it's not posi. So I am just wanting to see if I am looking for a limited slip/posi, that it MUST have the G80 code?? Thanks

Jason

P.S. VIN is 1G1BL52P7RR181025, which I already decoded.

I am in the search for a posi rear end for my car. I went to a local wrecker and they had a 94 Caprice 9C1 cop car package. I checked the spid on the trunk lid and couldn't find the G80 code. It had GU4 which is the 3.08 gearing. I was checking out on the net and what not, but I was under the impression that all 9C1's came with posi. The spid also has 9C1, LT1, and a bunch of the codes that indicated it was a cop car such as cooling for the oil and ps. So I wanted the diff cover pulled to check for any metal and to see if it is a posi or not. They called me back and said that it's not posi. So I am just wanting to see if I am looking for a limited slip/posi, that it MUST have the G80 code?? Thanks

Jason

P.S. VIN is 1G1BL52P7RR181025, which I already decoded.

All Posi's will have the G80 RPO on the SPID label. In my experience, most police package cars do NOT have Posi.

Having driven three Caprice 9c1's (and owned two), only one might have had the posi rear end (I say might because the SPID label was missing on that one). Both the white one and my new sky blue one did not have a posi diff. If it came from the factory with limited slip/posi, it WILL have the code G80. Now, just like engines or transmissions, it could have been installed later, but if it came from the factory with posi, it will have G80.

Thanks guys for clearing that up. I wish there wasn't false information being given out there elsewhere on the net. I will continue to look for one with the G80 code.

Jason

yeah it was a option, oddy enough though my civie caprice has a 3.42 pposi in it

People really like to delude themselves into believing the 9C1 and Impala were something more than a Caprice. All they really accomplish is myth building and missinformation. Half the "heavy duty" stuff they got is of questionable worth(external oil cooler, PS cooler, body bushings) and the disc rear brakes on the 94-9 9C1 and Impala don't function properly right from the factory due to the use of a drum proportioning valve.

The external oil cooler just randoml;y cools as opposed to REGULATING oil temps the way an in radiator cooler does, the 94-6 cars got more lower body bushings installed BUT were loose from the factory so that was pointless too.

I have a question then. Will a posi rear end w/ disc brakes from a LT1 function properly on my 1992 5.0 w/drums?

I have a question then. Will a posi rear end w/ disc brakes from a LT1 function properly on my 1992 5.0 w/drums?

Damn you if you found a rearend like that. =) Anyways check http://thebrakeman.com/articles it explains about a residual valve that might have to be removed.

You would need the ebrake cable and if your car currently has a 7.5" axle you would need the driveshaft too. If you have the 8.5" already then your current shaft is fine. The 9C1 has had the 8.5" since the 80s I know the civilian LT1 cars even got it I am unsure about the 91-3 civi cars. Summit or Jegs have picutes of the diff cover shape which can help you ID your current axle.

Yea i have the chance to get the posi rear end for $250 still just unsure about what everything i will need

Just got to looking at my SPID label tonite after buying my '94 Caprice and found out that it is a 9C1 and has the G80 limited slip rear. only thing that sucks is that it has the L99 engine.
Anybody know what kind of limited slip it is or who makes it?

Just got to looking at my SPID label tonite after buying my '94 Caprice and found out that it is a 9C1 and has the G80 limited slip rear. only thing that sucks is that it has the L99 engine.
Anybody know what kind of limited slip it is or who makes it?

I hate all of you. No posi units around here. Hopefully in time. Don't quote me but I think I remember reading Auburn made them, not sure. Also read on here that with the L99 you might have 3.23's, the spid will tell you for sure.

I hate all of you. No posi units around here. Hopefully in time. Don't quote me but I think I remember reading Auburn made them, not sure. Also read on here that with the L99 you might have 3.23's, the spid will tell you for sure.
According to the brochure, I should have 3.23's with the L99. Just wished I had an LT1.

abs might not work, not to sure though

People really like to delude themselves into believing the 9C1 and Impala were something more than a Caprice. All they really accomplish is myth building and missinformation. Half the "heavy duty" stuff they got is of questionable worth(external oil cooler, PS cooler, body bushings) and the disc rear brakes on the 94-9 9C1 and Impala don't function properly right from the factory due to the use of a drum proportioning valve.

The external oil cooler just randoml;y cools as opposed to REGULATING oil temps the way an in radiator cooler does, the 94-6 cars got more lower body bushings installed BUT were loose from the factory so that was pointless too.

It all depends on the car you get. Some of them really are more than an impala or caprice. But, on the main subject- yeah. You need that specific code for posi. Unless whoever you got the car from put it in themselves. I know I was not so lucky.

ABS will be fine.
The stock option posi was an Auburn, they are not rebuildable so most of us end up going to an Eaton which is rebuildable.