I sent Wilwood the measurements for my 15" Magnum wheels ,which the inside measurement is 145/8" and from the stud hole to the rim is 5 1/2".the kit that I am thinking about buying is P/N 140-11020
http://www.wilwood.com/Images/BrakeKits/WCD_Drawings/WCD_dwg-Large/ds757_wcd-lg.jpg

Any opinion and help if this kit will fit with the Magnum 500 wheels would be a great help.

Also is there any other measurements I should be looking at.