Depends on what Jeep you have. If it is a CJ with power brakes then a 77-81 Corvette MC is a strait bolt on and probably the best. A 79 Firebird with 4wheel discs can also provide a bolt on MC. 68-76 Corvette MC is often said to be a great bolt on for CJs with power brakes but the pushrod depth is wrong and it wont work(I beleive it will work great for manual brakes but I don't know first hand).