Gil Younger of TransGo Performance was the inventor & designer of valve body modifications over 35 years ago. These shift kits are a must for anybody wishing to improve economy, performance & durability of their automatic transmission.  Shift kits firm up 1-2 & 2-3 shifts & improve passing gear response.  These kits can be installed while transmission is still in the car.  We offer both the basic shift kit, which is geared towards the trained professional as it is usually installed during a transmission rebuild & may require  additional gaskets.  This kit is not recommended for inexperienced installers. We also carry & highly recommend our performance reprogramming shift kits.  These kits include everything needed to install while the trans is still in the vehicle.  These kits can be programmed to your different settings (off road, Pro Street & competition).  They also permit total shift lever control allowing you to manually shift up or down when you want, but without losing the automatic feature if you just want to stick it in "D".  Many of these kits have been engineered to correct inherent weaknesses that cause transmissions to fail, especially when dealing with more horsepower than stock.  Kits include detailed instructions, all necessary gaskets, a new filter, special drill bits, color coded components to help eliminate errors.