Hy Gazz, a lot of sites don't include trucks over one ton in their descriptions even when the parts are the same and will fit on trucks larger than one ton. As to your brake problem, it sounds to me like the master cylinder piston is not returning to its full at rest position. Is there a return spring on your brake pedal linkage? Have any adjustments been made to the linkage or master cylinder replacement lately? There must be a slight amount of clearance between the brake pedal linkage and the master cylinder piston, I believe the manual calls for 3/4" pedal movement before the master cylinder piston starts to move. If your checks reveal no problems in this area, then I would suspect the flexible brake lines may be "Check valving", good luck