The boost vavle out of my 67 switch pitch valvebody is bad and I was wondering if I could put one in from a 79 Cadillac TH400? Its the later style its steel and the holes seem smaller. Are these interchangable? Is one better than the other? Thanks - Justin
It goes inline with the pressure regulator valve. It is a small valve and has a sleeve with it. Its the first thing that gets popped out of the pump when your changing the regulator spring. Its held in by a snap ring. - Justin
You can swap the valve and sleeve assembly, have done that many times. However, DO NOT swap the pressure regulator valve. There are 2 types of valves used in the TH400. One has a hole in the end of the valve and the other (later style) does not. The one without the hole should never be used in the SP or earlier pumps. Only pumps with 895 cast into them can use the no-hole valve. Mark
Thanks for the info. I was also wondering what you guys thought of the transgo sk-400 shift improver kit. The car is my daily driver and I want to get more durability out of it I still want smooth sort of shifts but dont really mind if they end up firming up. My question is Do you think the Yellow Spring that comes in the kit will cause too high of line pressure? Thats whats holding me back from using it. What do you think? Thanks - Justin
