Curious about installing IRS

bigburl · Post by **bigburl** » Thu Sep 13, 2007 5:55 pm

Have the opportunity to pick up a 327 posi IRS from a 1990 T-Bird Supercoupe. How much work is involved in something like this and will it even go under my ranger? I really appreciate that so many of you guys are willing to help. Maybe some day I'll be able to return the favor.

Sleepy · Post by **Sleepy** » Thu Sep 13, 2007 6:44 pm

cheep? i seen the cobra irs for 2 grand usd.i seen then in pickups before with a clear bed floor looks nice but it would be a task good luck with it i had a cougar with irs before love it better then my live 8.8

broncobowsher · Post by **broncobowsher** » Thu Sep 13, 2007 7:07 pm

Watch the width.
I know you use 2 short side ranger axles (80's narrow version) when doing a cheap 5 lug conversion to 80's mustangs.
The thunderbirds and cougars are noticably wider then the mustangs. So the IRS would be at least 2 models wider then the early rangers.

That and there is no way to narrow the IRS very well.

But anything is possible with enough work thrown at it.

MalcolmV8 · Post by **MalcolmV8** » Thu Sep 13, 2007 7:50 pm

How much is cheap if you don't mind me asking? that's the same rearend the guys who build Shelby Cobra replicas use.

GregR · Post by **GregR** » Thu Sep 13, 2007 9:36 pm

The T-bird/Cougar 8.8 IRS (Supercoupe, XR7, V8s) are really pretty cheap. I can get them as complete drop out units at the local U-pull for about $100 each. The Mark VIII IRS is basicly the same except for the air ride and aluminum center section (like the Cobras).

Factory Five Racing uses the T-bird IRS in their Cobra kits. They have a "pin drive" option that includes narrower axles. Since FFR bases it's suspension on the Mustang, their IRS kit can be used to install IRS in a fox body Mustang.

Greg

bigburl · Post by **bigburl** » Thu Sep 13, 2007 10:35 pm

He's asking 125. for the complete setup. I don't know that I could fab what I need to to make it work. It isn't the actual fab work as much as being confident in the engineering. Broncobowsher, I can use two short side ranger axles in a four lug mustang housing? I hav an 89 mustang with a 410 posi already. Will the ranger backplates and brakes bolt to the mustang housing?

broncobowsher · Post by **broncobowsher** » Thu Sep 13, 2007 10:41 pm

bigburl wrote:He's asking 125. for the complete setup. I don't know that I could fab what I need to to make it work. It isn't the actual fab work as much as being confident in the engineering. Broncobowsher, I can use two short side ranger axles in a four lug mustang housing? I hav an 89 mustang with a 410 posi already. Will the ranger backplates and brakes bolt to the mustang housing?

No need to change backing plates. Use 2 drivers side axles and brake drums. Use the original brakes and backing plates. The front brakes are also Ranger units, but require the diameter (not thickness) to be turned down to fit the early mustangs. Most people now swap out the spindles for SN95 units with wider brake options. Old tricks from 20 years ago.

bigburl · Post by **bigburl** » Thu Sep 13, 2007 10:52 pm

Thanks bud, that's the easiest thing about this swap that I've encountered yet. On another note, is it safe to weld motor mounts to the cross frame? seems to me that putting the mount at the level of the cross frame instead of on top of it would allow the engine to sit considerably lower in the truck. In fact it might mean spacing it up just a little for pan clearance.

87ranger · Post by **87ranger** » Fri Sep 14, 2007 1:16 pm

they are cheap and ide love to it done