Navy-know what you mean--------however I have seen numerous (over many years since disc brakes )times that a package didn't work but that the person had no idea that his rear brakes weren't even working(post #86) ---when I get involved in something with 4 wheel brakes I take a very close look at an exact replication of something OEM-------Corvettes work fine, Lincolns, and Mustangs plus since so many use Ford 9iners rears , (or even 8.8) the explorer package does too. If not a race car I will look at the combo valves/masters from an oem and not mix anything up-------You got to remember that Speedway thinks brakes are to toss the vehicle sideways entering a turn on a dirt surface-usually ovals