Well there they are on 18's so don't need 20's. Dr diff has assured me they will fit on my 17's, so no don't need 20's. No custom parts needed either...
I think he was talking about the SRT brakes, and I think folks assumed that because the SRT's run 20's you'd need them.
For the 13" kits from Dr. Diff 17" is the minimum, I think there's probably some 17" rims that might not work, but most should. I just run 18's because that's where you see the big benefit of the tie rod end going inside the lip of the rim, so, backspacing options really open up.
For the SRT brakes, or the brembo 'style' brakes from doctor diff? The SRT caliper brackets bolt right on as well? Seems like it would be a more popular swap then, instead of using Cobra brakes for the rear and something else for the front. Let me know how that works out
I think you're confusing a bunch of posts and kits here.
Dr. Diff sells two 13" brake kits. One that uses 13" rotors and "cobra" style mustang calipers (PBR calipers), and one that uses 13" rotors and Brembo calipers. The rotors and caliper brackets are actually different between those two, only the hubs are the same.
Dr. Diff also sells a rear brake kit that uses mustang calipers, so, if you use the 13" cobra style kit up front you'd actually have mustang calipers front and rear.
As for the wheel sizes, the 13" cobra syle kit works with 17" rims, as I mentioned above. Maybe not ALL 17" rims, but it's been shown to work on a lot of the popular styles for these cars. The 13" Brembo kit I think would be more restrictive for rim size. I don't know for sure if they'll work with 17" rims, I know the calipers are larger than the "cobra" style calipers so at best I would suspect that there would be less 17" rim styles that would work with the Brembo's.
All of Dr. Diff's kits are bolt on. No one that I'm aware of makes
any kind of kit for the modern Mopar SRT brakes.
