I used this kit way back when...anyway it was on a six liter, I never liked it. Had a local guy build a trans with it years ago. I had the same issues you were explaining, where it would blow off the needed pressure to shift. I eventually melted the clutches together because it was releasing that needed pressure at higher RPMs. The shifts feel like a stock trans, not much of a shift kit at all as described above. I tried removing the kit when I first started the problems ,but it is drilled and tapped into the pump iirc. I tried plugging it and all, but it just went downhill from there with heating expansion leaks and so forth. Hope this helps!