pressure valves
you only need pressure valves if the master cylinder is mounted lower than the brakes on the car, if mounted to the firewall no valves are needed, but if under the floor you will need them, and you will deffinetly need a porpition valve (dont think i spelled that right) adjustable is the way to go, that way you can adjust pressure from front to rear and get a good balance so evey time you hit the brakes you dont either lock up the rear wheels first or slide the front wheels, you can adjust it so the whole car slows down and no sliding