shift kits will not only make a difference in how you feel the shift, but they also help in transmission longevity. cars and trucks from the factory are meant to have a nice smooth shift that is comfortable to the ride of the vehical, this smooth shift comes due to a larthargic shift with little line pressure on the cluthes causing them to slip untill they are in the next gear. shift kit takes away that prolonged time betweeen gears which takes the slipping ouut of the trans and reduces wear on the clutch plates and steels.
awesome read right here on shift kits improving durability and performance of the trans
http://www.txchange.com/transgo.htm