Thats what i have heard, but the wilwood kit does claim it works with some 15” wheels, and if i did my math right, requires an inner diameter of 14.12 to work.
The problem with vintage wheels is that some of them are carry overs from the drum brake era so they do not have the internal clearances to allow disc brakes to fit. In some cases this is due to large rotor diameters and in others it is the spoke clearance for caliper width. Some 500s may lack the radial clearance to allow the wheel to sit flat on the disc face because of caliper width. Some do not. Depends on when they were made. Rallyes typically do not have this problem because they are a later design with disc brake compatibility designed in, but may be diameter restricted, depending on caliper bridge height. You also have the nose of the hub issue pointed out above. This may require turning down the diameter of the whole nose section, not just the cap, to fit through the 500 hole, or opening up the wheel to allow the nose to protrude through.
This has been discussed a bit before. Find it here:
https://board.moparts.org/ubbthreads/ubbt...tml#Post2565418I doubt you'll fit a 12.19" rotor with a 15" wheel. Typical rule of thumb (from personal experience) is whatever the wheel diameter is, subtract 3" for MAX rotor diameter. So a 15" wheel could hold a maximum 12" rotor. However, this rule can be violated, especially with a tall caliper or a wheel with a thick barrel (like OE wheels).
Actually, 12.19 is the max diameter the nascar boys run, so it is possible and this kit in particular was designed for that application. But again, later model wheels have been made with disc compatibility in mind. My Aero wheels will fit these just fine. OEM wheels from the classic era are a big variable on what will or won't work. Even some OEM and aftermarket wheels with 11.75 discs and different calipers like Dynalites , Vipers, etc. are a wildcard. I've test fit a number of them over the years and some work, some don't.
