MassMustang
Senior Member
Jumping on an older thread, but if you decide to swap out the FRPP springs, I'd be interested. I only want 1.0"-1.5" drop and I'm running 295/45/18s in the rear.

Get these springs from UPR and you can set the height for whatever you want. I have these on mine and they are a good product.
http://www.uprproducts.com/mustang-adjustable-rear-spring-mount-05.html