Adjustability in custom IRS?

[MyCreation68]

I'm just going to toss the question out there. Seeing as I'm building a custom setup IRS for my dart with parts from an early 90's ford thunderbird. I'd like to get as much adjustability out of the rear suspension as I possibly can so I think I'm going to go with an adjustable upper control arm with some sort of threaded adjuster and I'll have to make the lower control arm with the air bag mount on it and I'm not sure of how to adjust it maybe heim joints? or maybe a shorter threaded adjuster? not sure. Maybe somebody could give me an idea?

[sunsetdart]

I didnt know early T-birds even had IRS. I'm hoping the IRS means independent rear suspension, and if that's what it means, I'm still wondering when Ford made one for the T-bird.

[abqdart]

early 90's Thunderbird and Cougers had an IRS. It was an 8.8 center section with half shafts. They also put them on certain year Cobra's. Cant remember which ones. Good luck with the build. Have you just thought about grafting in the whole dang thing with "maybe" only having to fab up mounts and brackets and then custom length halfshafts?? There is a guy in Car craft or Hot rod that uses C-3 and C-4 Corvett rearends in Gen 2 and Gen 3 camaro's and Firebirds. Say's its "ALMOST" a bolt on!!!!

[MyCreation68]

the thunderbird irs is to wide to fit in the dart which is why i have to custom make lower control arms and uppers.

[abqdart]

good luck! dont forget to post pics as ya go! Should be an awesome handler

[MyCreation68]

good luck! dont forget to post pics as ya go! Should be an awesome handler

Thats the goal. I decided to go ahead and install a cage anyways. I want this car to be as solid as possible so I'll be custom making a cage that won't be in the way of actually using the car so I'll have complete functionality of the rear seats and everything else.

[sunsetdart]

That's why I come on this site..............I just learned something I never knew.........just goes to show ya

[loiq]

The thunderbird IRS is the same as the lincoln and the same as the Mustang. The lincoln is all aluminum so it is lighter than the t-bird. They came with both 8.8 and a smaller diff, a 7.8 I think? Hub to hub is something like 60 inches and the five lug pattern is some funky metric size, it doesn't match a 4.5-inch circle.

As for the C4 Corvette IRS, the cradle for the diff (called the batwing) is too wide for the frame rails, so that would have to be shortened or you'd have to mod your frame. I'm sure the hub to hub is too wide, too. You'd also have to fab a mount for the pinion snout since that uses a c-beam in the corvette that hooks the diff to the tranny.

Here's info on converting a jag IRS for use in a Mustang: http://home.bresnan.net/~dazed/JaguarIRS1.html

[Arillious]

not trying to steal the show, but why is it that a solid rear end is better than irs? or rather when is a solid rear end better than irs?

[MyCreation68]

not trying to steal the show, but why is it that a solid rear end is better than irs? or rather when is a solid rear end better than irs?

Solid rear=drag racing
irs=road course.
I have no interest in 1/4 miles I like things like watkins glen.
the smaller IRS is the 7.5 ford diff, it's strong enough for a stock slant but The 8.8 is better. the lincoln while being all aluminum is nice but the thunderbird one only has a steel diff housing. everything else is aluminum.