I am not 100% positive, but it seems that all the kits are made by the same company, They all use the 1.125 MC. on all years. Only difference i see is the adapter plates. Of all the company's selling these , Race craft is the only one to declare that you need the 4 piston calipers for proper function. I bought the unit from JPC and it works, but it does take too much effort. I am going to reinstall the stock MC if it fits the adapter plate, w/o the booster just to see how it works.