Caprice Rear Axle Swap

[Richard D]

I did a search and found nothing. From what I've read, they are about 3" narrower and still have the 5 on 5" bolt pattern. Seems as if a guy was handy with a welder, he could put leaf spring perches and get a narrowed rear end on the cheap. Or if you want a 4 link it's ready to go.

[Loco83]

Tell me more.

[Richard D]

I'm still a fan of 15" wheels. I have some 10" aluminum slots I think would look good tucked up with an 8" drop, but they are only about 3" backspace. I like the deep dish look, but would need a narrower rear axle.

[Ziegelsteinfaust]

First thing you need to do is mount the wheels, and get a good total width measurement.

Sounds like your in the ball park of width needed, but a Chevelle rear may be close too. When done you can compare wms differences to see what to do.

The 4 link is easy enough to add some metal to the frame to get it to work, and makes bagging the truck easier in 1 swoop.

A simple out rigger for the mount, and a support brace would work. For most unless your going to seriously hammer it with big hp on sticky tires. 2x3 1/8th wall would work for the outriggers, and a triangulation with 2x2 1/8th box would be fine.

With big hp the out riggers may bend, and force the frame in ways it may not like.

I did it for a kid who had a C10 which was only 2.5 maybe 3 inches at the frame. He had the mighty 4.3 Vortec V6. Which he wanted for mpg, and so he couldn't get going to fast to low. Plus it was 250 for the whole van it was in.

I don't know why my post is angry?

[Richard D]

Reason I specifically looked at Caprice, is the availability.

[Loco83]

Are there certain years to be aware of or look for?

[Ziegelsteinfaust]

Originally Posted by Loco83

Are there certain years to be aware of or look for?

Appartently the full sive chevy frame changed very little from 70 or so to 96 as a whole when disk brakes were introduced. And back to 65 if you do not mind drums.

There were some small changes, but I know lots of stuff swapped around.

[SCOTI]

Originally Posted by Richard D

I did a search and found nothing. From what I've read, they are about 3" narrower and still have the 5 on 5" bolt pattern. Seems as if a guy was handy with a welder, he could put leaf spring perches and get a narrowed rear end on the cheap. Or if you want a 4 link it's ready to go.

You'll want to verify axle tube size. The later Caprices & the ones w/the disc set-ups might have smaller axle tubes. Something to verify since most leaf axle pad brackets are 3". I know other housings under cars of the era had smaller diameter tubes; not sure on those.

You're correct on the fact that it could be a poor-mans narrowed housing. There are also lots of others that can fit that need. Knowing the best (closest) width for your wants is the starting point. Measure the distance between the farthest outboard portion of the fender openings where the tires might rub. Factor in the wheel width/back-spacing to determine what rear-end width will work. Google rear end widths for more info & that should help guide your options.

[Richard D]

I don't even have a C10 at the moment. I've been working on my old 'Vette, and my friend has been over helping me driving his rusty C10. It has the front clip off my old red truck, doors off my old white truck, and it's original blue bed. Patriotic! I still have a '53 F100 I want to get back on the road, but I definitely want another C10. Just doing some mental planning...

[tinydb84]

You are looking for the 9C1 rear. I believe 96-98 if I remember correctly. Disc and posi from the factory. Same 5x5 lug spacing. They also came in Impalas. I know a guy who did the swap. Used new perches and switched to a disc/disc master cylinder and proportioning valve. I dont remember what he did for the U joints.

[Richard D]

That's just what I was thinking, police car axle. Was thinking it would be a good swap.

[Pontiac1976]

Police car and SS car Option package 10 bolts have the 5x5 bolt pattern 15" you want the later one mostly

[Rich84]

I think some Astro vans are 5 lug with disc brakes too.

[Wgesnerjr]

Be careful. Station wagons had 1 inch wider rear. This was because chevy advertised ability to carry 4 x 8 sheet of plywood flat on floor.

[SCOTI]

Pretty sure the use of these housings for alternative vehicles is known throughout gearhead circles. I can't think of the last time I saw an actual 96-98 SS car in a yard. The cop cars are pretty scarce as well.

[Pontiac1976]

This included Reg- Caprice and (Taxi cab's )-most did come WITH OPTION of SS or Police car = bolts have the 5x5 bolt pattern 15"
the option code I for get now But not all taxi cabs had it because there was a lot of them left over the rent cops, fire departments chief, military cops bases, air port base cops. You check them to see if they had the option most would as they get some deals on buy.

[D13]

It's the police pursuit and Impala SS's that got 8.5" axles and disc brakes. 95% are 7.5" axles and/or drum brakes.

[hatzie]

Originally Posted by tinydb84

You are looking for the 9C1 rear. I believe 96-98 if I remember correctly. Disc and posi from the factory. Same 5x5 lug spacing. They also came in Impalas. I know a guy who did the swap. Used new perches and switched to a disc/disc master cylinder and proportioning valve. I dont remember what he did for the U joints.

The mid 1990's 92-96 Cop package (RPO 9C1) B-Body Caprice and Impala SS had rear disc brakes and 4 link coil spring solid axle rear suspension.
The B-Body Caprice and Impala ended production in 1996. The only big V8 cop/taxi cars after that were the 1998-2011 Ford Panther platform Crown Vic
There was no such thing as a 1997-1999 Caprice or Impala.
The 2000-2019 Impala was FWD. I believe the Impala has disappeared into the sunset again.
The 2011-2017 Caprice PPV was actually a RWD Holden model that came with a 6.0L V8 & 3.6L V6 but it's significantly smaller than the 1990's B Bodies. Closer to the 06-17 W body Impala.

I believe the B-Body axles are narrower than truck axles.

[SCOTI]

Originally Posted by hatzie

The mid 1990's 92-96 Cop/Taxi package (RPO 9C1 or 9C3) B-Body Caprice and Impala SS had rear disc brakes and 4 link coil spring solid axle rear suspension.
The B-Body Caprice and Impala ended production in 1996. The only big V8 cop/taxi cars after that were the 1998-2011 Ford Panther platform Crown Vic
There was no such thing as a 1997-1999 Caprice or Impala.
The 2000-2019 Impala was FWD. I believe the Impala has disappeared into the sunset again.
The 2011-2017 Caprice PPV was actually a RWD Holden model that came with a 6.0L V8 & 3.6L V6 but it's significantly smaller than the 1990's B Bodies. Closer to the 06-17 W body Impala.

I believe the B-Body axles are narrower than truck axles.

Just a quick Google found this so accuracy would need to be verified:
https://www.impalassforum.com/thread...nsions.556337/

There are 3 different widths, 1566mm, 1598mm (both sedan), and 1642.5mm (wagon). This discussion is primarily about the sedan axles. I "believe" that the width dimension refers to the distance from axle flange to axle flange--without disc or drum thickness added on.

The 1566mm axle (61.65") is used on 8.5" axle applications only, with both disc and drum brakes, depending on the car (taxi = 11" drum with 2.93 or 3.23, police = disc with 3.08 or 3.23)

The 1598mm axle (62.91") is used on 7.625 & 8.5 applications, both disc & drum, 2.56, 2.93. 3.08 & 3.23. Impala SS is the ONLY 1598mm axle with rear disc brakes, and is the only wider axle that used 3.08 ratio.