M-5300-BR Springs

[ihatepotholess]

I'm pretty sure that the Eibach Pros are the same as the FRPP-badged 'P' springs (Eibach makes them for Ford), which I am running on my '13 LS. I know there is a thread somewhere with the rates compared between several brands of springs. In terms of feel, the P springs are slightly firmer than OE, although not nearly as firm as the Steeda Ultralites I had on my '12 Boss (which were still pretty tolerable on the street).

I think that if I had to do it all over again I probably would have put on Steeda Sports, which are in between the Ps and the Ultralites in both spring rate and drop. If I had never run the stiff Ultralites I probably would be very happy with the Ps but the Ultralites kept the car SO FLAT through corners and under braking and I miss a little of that.

I wasn't aware that Steeda made two sets of springs for the Boss. Stock springs are too soft for my liking nowadays. Hopefully Pro Kit is significantly firmer. I don't mind rough ride on the street.

 

[Champale]

Any of the springs made for the '11-'13 GTs will work on the Boss, there is nothing shock, strut, or mounting related that would prevent it. The Steeda Ultralites, Sports, and their Boss-specific springs will work on the Bosses and GTs, just like the Ford P springs are not specific to the Bosses.

I think that you would be happy with the Ultralites. Makes the car even more responsive without completely killing the ride or being so low that you scrape everywhere (although you might consider sawing off the tips of some of the low-hanging exhaust bolts with any lowering springs).

I would highly recommend calling Sam Strano. He has a wealth of knowledge and his prices are pretty decent, too.