Beginers luck (not)

[OKBODYMAN]

I am the proud owner of a FFR mk4 kit. It was given to me as a gift from my employer for 30 yrs of service. Unfortunately i have allready hit my first snag. I purchased a 2003 mustang cobra IRS assy, only to find that it will not bolt right in. I never read anything in the assy manual indacateing that it would or would not work. Has anyone else ever made this mistake? If so, how did you fix it? My thought is to modify the frame, but i'm not sure? Any help would be appreciated.

[LMH]

I'm not an FFR MK IV expert but on the older models, you need the IRS cage and suspension. Did your's come with the cage?
You can use the differential and CV joints out of the Mustang set up. The diff should be aluminum if it's an 03 Cobra Mustang and the inner CV joints are 31 spline. You'll need knuckles from a Thunderbird/Cougar as well as brakes I think. Not sure about brakes though as you may be able to use the Mustang brakes.
You'll also need to swap out the axle center shafts for the correct length shafts. They are available from FFR I think as well as a couple after-market suppliers.

Maybe one of the FFR guys with more knowledge about the MK IV will chime in with better info.

Good luck with your build!
Larry

[dallas_]

The FFR frames come set up for different rear end suspension options.
Call FFR and tell them which kit number you have and they can tell you what it's set up for. If it's not set up for IRS they can guide you on what your best options are.

[Three Peaks]

ffcars.com

[Clois Harlan]

Call me if you need some help, I have a little experience with the FFR IRS on a coupe. Mine used a 90's model T-Bird. By the way I have some new axels if that I will give you if you need them. PM me and I will send you my telephone number.

Clois Harlan