Ok, what is Stem Height? It is the amount of the Valve Stem that Extends beyond the Valve Spring Seat. For example, a common Spring Height Install is 1 inch 600 thousandths. So, when the Valve is Closed, or on it's Seat, when the Spring is Installed with the Retainer and Keepers in Place it should be 1.600 Tall. Now, assuming your valves are in Align, then every valve will open the same distance!
