Curious what RPM were you turning the engine? Have similar issues with my deal but a solid stem 2.18 valve and a beehive manley spring. My issue is I will need to change all the valves to get a dual spring on it. Thinking about a PSI 1516 spring and 2.18 hollow stem valves. Turning my deal 7500 but it is not happy at all in the valve train department.