IRS Question

[klkordzi]

Hi all,
I'm new to this forum but not to rebuilding cars and fabrication. I'm starting my planning for a truck project with a 60-65 Chevy truck. In looking around at LS engines and options and I came across an IRS from a Cadillac CVS-R. LKQ sells the entire rear with crossmember for around $600 and this got me thinking about how difficult would it be to install. Does anyone have any thoughts or opinions?

[spousta]

Anything is possible dependent on your fab skill cant speak for the caddy irs but i made a mark viii irs work, i thought it was kinda a easy job took me 2 atempts just to get my ride height correct but it should be no diffrent from the cady setup
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[smashingchuck]

Sure you might be able to do it, but adapted IRS's always look like just that, an IRS out of some car welded to your truck.

[spousta]

Who sees it though when its covered by a trck bed, no diffrent then Trans x braceing
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[N2TRUX]

Originally Posted by smashingchuck

Sure you might be able to do it, but adapted IRS's always look like just that, an IRS out of some car welded to your truck.

I disagree. It really depends on the IRS. Some are rather bulky and others are packaged much cleaner. I don't have pics on this computer, but the frame that Nate porter built for n2billet with full Corvette suspension was very clean.

[smashingchuck]

Originally Posted by N2TRUX

I disagree. It really depends on the IRS. Some are rather bulky and others are packaged much cleaner. I don't have pics on this computer, but the frame that Nate porter built for n2billet with full Corvette suspension was very clean.

I guess I didnt realize the CVS-R had the same differential as a Corvette, and that nate was doing the fabricating.

[N2TRUX]

Note that I said I said that "It really depends on the IRS. Some are rather bulky and others are packaged much cleaner." Further research shows that the Cadillac fits in the bulky category.
Sarcasm aside, my point being an IRS can be made to look clean, it just depends on the time and effort put in to the design.

[Scottshotrods]

Agree 100 percent

Justin
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[Bomp]

Im not sure what all would be involved but heck. What fun is there in doing a job in one weekend? Go for it!
Oh, and welcome to the forum.

[andrewmp6]

It depends a lot on your fab skills but anything can be done.If it was me i would see what the track width the caddy is and your trucks see which ones wider.

[jimmydean]

CTS-V is a different (not very, but different) rear end than the Corvette. My buddy has a 2005 CTS-V and 2005 C6. The rear end on the V uses a different mounting system and is a bad design in the Cadillac. If you are building your own back half, you can correct the issues the Caddy has. But know that the parts for the Cadillac are a lot more than the Corvette rear and I don't know if anything is interchangeable.

You would THINK GM would have used the same rear, but that would have been too easy. A lot of guys destroy the rear pinion on the CTS-V, but they now make a pinion brace that helps a lot.

[MAK191]

I know it's not GM but you could check out some of the newer Nissan SUVs (armada, pathfinder) They have irs, disk brakes, and the correct 6 lug pattern. Only question is how wide they are.
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[klkordzi]

I think this is worthwhile exploring if only from a cost standpoint. LKQ sells the entire assembly for $500.

[N2TRUX]

My next question would be...why? Yeah I know it sounds cool, and it would be different. I get all that, but I still have to ask is that your only end goal? If so are you will to cut a hole in your bed to show it off? If not, we go back to the original question of ....Why?

Its great in theory to play the "what if" game. Beyond that, I don't see a big enough advantage to make it worth the effort.

[N2TRUX]

BTW- The Nissan axle isn't very pretty either...

[andrewmp6]

Jimmydean the c6 is a transaxle and i believe the cts is based off a holden.

[blazins10]

the 05 and up nissans are a different 6 lug pattern
6 on 4.5
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[snoopy]

Nate is doing the chassis for my crew cab c10 now and it will have IRS. All the control arms are from a z06 corvette and the center section is quick change from Dutchman.

[paintman]

WOOOOOO!

[klkordzi]

The question I had in my had when I started this thread was whether an IRS from a Cadillac or some other vehicle be a cost effective option with an additional value added effect of increasing handling. LKQ will sell you the entire rear end including cross member for $500. That seems to be a deal when compared to the cost of a conventional rear end. To a degree, fab work is not a concern but I'm also wondering what would have to be done to install it.

[twich3136]

for $500 thats awesome! the whole thing for 500-600. if you can mount it run it. its just metal. i cant find a decent new solid rear end for that price.. but im looking to lift and tow. if you can do it i say go for it and post many many pictures of the build and how it performs.

[wraprail]

The Cadillac CTS-V (2004-07) rear diff is known to be weak and prone to breakage. The aftermarket diff support actually makes it worse. I know this first hand as I owned a 2005 model. Fastest car I have ever owned, by far. I have a vid going 161mph. Ran 156mph in the Mojave Mile in 2011 and it was stock. The diff however is garbage.

[jimmydean]

Originally Posted by wraprail

The Cadillac CTS-V (2004-07) rear diff is known to be weak and prone to breakage. The aftermarket diff support actually makes it worse. I know this first hand as I owned a 2005 model. Fastest car I have ever owned, by far. I have a vid going 161mph. Ran 156mph in the Mojave Mile in 2011 and it was stock. The diff however is garbage.

NICE!

When Joe got his Caddy, it had an awful clunk under hard shifting. Some aftermarket company made a pinion brace the stiffened it and eliminated the clunk along with a new bushing. We did it the same time we did the monster clutch kit and found out the Caddy uses a slightly different clutch as well. The remote bleeder for the Caddy was straight while the Vette had a slight bend in it. had to tweak it to fit, but it works like a champ now and the monster clutch remote bleeder is mounted in the engine compartment so you don't have to crawl under the car anymore.