andrewmp6

The 99-04 cobra irs is pretty much the same every year.And you can get one cheap there's always post on every mustang forum wanting to trade one for a stock 8.8 out of the same year cars.But if you get one the diff brace is a must if you want high power or drive like a idiot like me lol.

Obsidian71

Well, I checked out what used to be DVS Restorations website which is now http://www.davestriblingrestorations.com/ At one point a few years ago when I did the bulk of the work on mine there was an abundance of information on putting a '99-'04 Cobra IRS into '67-'70 Mustangs. I did some homework on my own and found that there were really minimal if any differences in the key measurements of the rear framerails from '67-'73 so I figured I'd look deaper into it. What I found out is it actually fits better in the wider '71-'73's. The rails are in basically the same location as the earlier cars, but us '71-'73 lovers have a closer track width to the SN95 chassis. So rather than pay over $1500.00 for a few bolt on brakets and a pair of coilovers they sell in kit form, I figured I'd make my own brakets and weld them in. I still haven't done anything about shock/spring mounting yet because I'm still unsure if I'll go coilovers or air ride. Hope this helps! If you have any other questions let me know, I'll try to maybe find some of my old magazine articles on this and see if they're still availible in the online archives.
Nice to know there's someone else out there looking to do something different with a '71-'73.

andrewmp6

Air ride on it is easy since the mark8 had it and the cobra irs is based off the one the mark 8 the cougar and thunderbird got.

THUMPIN455

I am trying to figure out something to do with the 71, because honestly I dont have a use for it. No burning desire so to speak. Initially I was going to rebuild and sell it, but I wouldnt have made anything on it when it was finished, and that is with me doing everything but the machine work on the engine.

So I have been considering making it turn really well, or build it for top speed challenges. IRS would work well for both of those. So that is the same rear that Cougar/TBirds/Lincolns have under them? Seems that Mustang parts bring out the stupid in people up here even if they are the same thing that is under something more pedestrian.

I have lots of Cleveland parts, and a 460 that would like some aluminum heads with a stroker crank. I forget how many 302s I have, its plenty, so engine choice is open. Im not a fan of the mod motors, lots of money for not a lot of power IMO.They are cool being cammers, but the bores are just too small for me and most need a blower to make decent power. Not ripping on them, its just how I see them. Getting one isnt a problem, making it run hard is.

The 71 is so rusty in so many weird places that really it would be a crime to sell it to someone as a restoration. If I could find one of those rear ends, and make the front end better then it could be a fun car. I wouldnt even mind having gears in the 2s or low 3s. Actually that would work quite well for what I want to do with it.

andrewmp6

The tbird cougar mark8 irs is bigger heavier and kinda weaker.The cobra one is upgraded a lot and has a lot more aftermarket for it.But look for trades on here and other forums i see post here and there a even trade for a 99-04 8.8 which are not that hard to get.You could use the air ride off the mark8 tho.

Rols574

I actually wanted to do the IRS on my 67 as well and was saving up for the brackets. can you share the template or a picture of your brackets? both?

Thanks

NoReins

Oooo lookin good. Get back to it! I will definitely be following this thread.

Obsidian71

I don't have any templates, I based it off of close up pics that used to be posted on DVS Restorations website and kind of "floated" the rear in place with the car set at an approximate ride height and made the brackets around it. I'll dig through my files to see if I have the close up DVS pics and take some close ups of mine as well. Give me a few days though...

Rols574

Thanks I'd appreciate that

andrewmp6

Its not that hard if you can weld,On trucks! they put the same irs under a mazda pickup they are working on.