IRS/Solid Swap

[AaronK]

I'm going to swap a guy with an 03 Cobra IRS for my stock Mach 1 rear end setup. I actually have an 03 Cobra also and have done a solid axle swap on it and had two different IRSs in it also so I"m fairly familiar with the swaping on the Cobra side of things.

That said, I've never had to deal with 100% stock rear ends. Therefore, I don't know what's needed to make the driveshaft work. I've heard some people like swapping the pinion flange and someone said something about doing a different U-Joint??

Anyone know what type of ujoints I will need and the guy with the cobra would need?

 

[brian97cobra]

i swapped the pinion flange in mine. however the smartest thing to do is keep the cobra flange on the irs. call MPS auto salvage and order another flange. if you remove that flange it makes that irs worth a lot less because then the crush sleeve would need to be replaced and retorqued and such.

its not a hard swap.

get some upgraded control arms upper and lower, also get some axle houshing bushings. now would be a good time to do a gear swap axle swap and upgraded cover.

i high recommend 31 spline trac loc and 31 spline axles 3.73 gear

remember that factory SRA came with a 28 spline trac loc and 3.08-3.27 rear gears depending on what model you have.

the cobra has a 31 spline irs from the factory.

 

[stal94gt]

if you have the 03 cobra and want to go with the sra out of the mach the easy way to do it is the persision 448 u joint. you can get it on summit
Precision Universal Joint 448 - Precision U-Joints - Overview - SummitRacing.com
this u joint will allow you to convert the flange on your drive shaft to a gt one.

or you can get the 03-04 pinion flange and have it installed on the new rear end
2003-04 Mustang Cobra Pinion Flange by Ford Racing at LRS - Same Day Shipping!

 

[AaronK]

i swapped the pinion flange in mine. however the smartest thing to do is keep the cobra flange on the irs. call MPS auto salvage and order another flange. if you remove that flange it makes that irs worth a lot less because then the crush sleeve would need to be replaced and retorqued and such.

its not a hard swap.

get some upgraded control arms upper and lower, also get some axle houshing bushings. now would be a good time to do a gear swap axle swap and upgraded cover.

i high recommend 31 spline trac loc and 31 spline axles 3.73 gear

remember that factory SRA came with a 28 spline trac loc and 3.08-3.27 rear gears depending on what model you have.

the cobra has a 31 spline irs from the factory.

I'm actually the one receiving the IRS and installing it in my Mach 1 (daily driver). Thanks for the advice though.

if you have the 03 cobra and want to go with the sra out of the mach the easy way to do it is the persision 448 u joint. you can get it on summit
Precision Universal Joint 448 - Precision U-Joints - Overview - SummitRacing.com
this u joint will allow you to convert the flange on your drive shaft to a gt one.

or you can get the 03-04 pinion flange and have it installed on the new rear end
2003-04 Mustang Cobra Pinion Flange by Ford Racing at LRS - Same Day Shipping!

Would this u joint work on both the mach 1 and the cobra??

Is there any concern about the length of the driveshaft?

 

[stal94gt]

if your getting the irs out of a 03 cobra that u joint will work. the stock mach 1 drive shaft is fine as long as you still have the 3650 trans in. the drive shaft will sit a little deeper in the trans but not enough to matter. when i bought my 03 cobra i kept my gt so i could do the swap. the only part i needed to buy so i could swap the parts over were the 2 u joints (1 for each car).

 

[AaronK]

if your getting the irs out of a 03 cobra that u joint will work. the stock mach 1 drive shaft is fine as long as you still have the 3650 trans in. the drive shaft will sit a little deeper in the trans but not enough to matter. when i bought my 03 cobra i kept my gt so i could do the swap. the only part i needed to buy so i could swap the parts over were the 2 u joints (1 for each car).

Thanks! How hard is it to replace u joints? ... same u joint for each car right?