t-bird irs dimensions

stanglou · #1 (**permalink**) 06-21-2005, 12:37 PM

can anyone tell be the dimensions from brake mounting surface to brake mounting surface for the 89-97 t-bird supercoupe irs swap. also, what is the bolt patern on the irs and can it be changed to 5x4.5?
thanks for the help, im trying to adapt it to my mustang if it is possible.

Three Peaks · #2 (**permalink**) 06-21-2005, 12:55 PM

The T-bird IRS is too long for the mustang, but you might want to check the Mustang Cobra's with IRS. I think they are the right length for your mustang and come with the mounting cage already set up. All you have to do is bolt it in with 4 bolts, I think.

Check the classified ads on www.corral.net for Mustang parts. The Cobra IRS comes up quite often from guys changing over to straight axles.

The T-bird hubs can be redrilled for the Mustang 5 x 4.5", but the Cobra IRS is already the right bolt pattern. So, you can either have the T-bird unit redrilled for around $75 including shipping, or buy the Cobra spindles for around $85 for the pair.

stanglou · #3 (**permalink**) 06-21-2005, 01:36 PM

by too long do you mean that the track width is too wide? how do all the people here fit it in their cobras?

Three Peaks · #4 (**permalink**) 06-21-2005, 01:52 PM

Yes, the T-bird has a wider track width.

Installing one in a Cobra is a completely different ballgame than trying to retrofit one into a Mustang.
It can be done, but you'll have to add all the mounting brackets, a subframe, and shock mounts and suspension pick ups to your existing frame. Then, you would need to have the axles shortened and the hubs drilled to the Mustang bolt pattern.

If you can find a Cobra unit, it should practically be a bolt in.

Cobras that are designed for the T-bird IRS (such as FFR) have all these points in place so it is a bolt in proposition.

Check with some of the Mustang forums to see how difficult it would be to do the retrofit. I'm just not that familiar with Mustangs to be sure.

stanglou · #5 (**permalink**) 06-21-2005, 02:41 PM

any idea what the dimensions are/track width

Three Peaks · #6 (**permalink**) 06-21-2005, 06:24 PM

Don't know the dimensions of the T-bird IRS, I didn't measure mine while it was still in one piece.

If you check in the "Parts for Sale" forum above, you'll see a guy has a Cobra IRS for sale for a darned good price. Check it out and see if the track width will fit your Mustang. What year Mustang are you thinking of putting it into?

Jay Little · #7 (**permalink**) 06-22-2005, 09:08 AM

It's been over a year since I saw the post, but if you do a search on www.corral.net, you will come across several guys that have fitted the Cobra IRS to their Mustangs. From what I recall, the modifications are few (drilling holes into the subframe), and is almost a direct bolt in. One guy had LOTS of pictures documenting his build. (look in the Fox body section) Good Luck.

Jay Little

Ant · #8 (**permalink**) 03-19-2006, 03:01 AM

What size wheel studs (7/16" or 1/2") are you going to after these hubs are redrilled, as the holes are getting reasonably close to the outside?

grumpy · #9 (**permalink**) 03-19-2006, 08:26 AM

stanglou,
stock t-bird irs wheel mating flange surface to surface is 63.50" +/-.
grumpy