This valve body kit deals with these problems: Sloppy 1-2 shifts Erratic 4-3 shifts Throttle valve sticking Inadequate line pressure rise Extends band life .471 boost valve included to replace worn OE valve. 1. Throttle valve sticking is a very common problem in the 200-4R. This Shift Correction Package deals with the problem by changing 2 springs in the valve train. Many shops may have valve bodies sitting unused due to this problem. Superior can fix it! 2. Pressure rise problems can cause premature failure. The replacement of the pressure regulator and line bias springs, contained in this valve body kit, will give full positive response of pressure in the 200-4R unit. 3. A high performance version of this kit (K200-4R-HP) is offered for street rods, racing and extreme heavy duty use. This kit supplies a big TV boost valve as well as valve body modifications. This keeps the apply pressures up to needed capacity and delivers it to the band and clutches quickly.