I like to see no line pressure increase when adding a chip or tuning. Part of what a vb does is channel pressure where and when it's needed. The other improvements are made in the pump. It's all a system that has to work together. Too much pressure can cause bind @ shift points as valves fight each other. Thats what the situation sounds like in this thread: http://www.thedieselgarage.com/forums/showthread.php?t=30606youngPSD said:Is the best bet when i get a DP Tuner is to have a upgraded valve body put in for a better tranny life?? What valve body is the best? Should i have the valve body put in first then get the chip.. i need some opinoins!!