I'll do you one better. I found these to install with my H&R springs. Free shipping too!
Spring Isolators Springs Suspension 2003-2004 Ford SVT Cobra
No reason not to buy these, unless out of stock, because they are cheaper than the price of the other ones alone with (Free Shipping)! So you win all the way around.
You would still have to buy 2 kits..There is 2 different pairs of insulators in that kit..Only one of which we can use on our cars..
The 99-04 (IRS) Mustang Cobra uses the same lower
rear insulator as the MN12..
The 99-04 (IRS) Mustang Cobra uses a different upper
rear insulator than the ones used on the MN12..
The MN12 uses the same insulators on the top, and the bottom of the rear coil spring..
You can see the difference in these pictures between the upper
rear spring perch used on the Cobra vs the MN12..
Cobra (IRS) Rear Spring Perch.JPG
MN12 Rear Spring Perch.JPG
IMO..If Ford would have thought the upper
rear spring insulator used on the MN12 would have been suitable for the Cobra they would have used it..
Instead they used a Mustang specific upper
rear spring insulator based on the shape of the upper
rear spring perch used on the Cobra..
IMO..Our cars would be better suited to use only the lower
rear insulator offered for the 99-04 (IRS) Mustang Cobra..
Since our cars do not share the same upper
rear spring perches..