454 race build
I would pull the heads to see if you had valve to piston contact. Check the pushrods by rolling on flat surface. What is the brand and part# of the pistons?What is the Part# of the camshaft? Also do these 115cc chamber heads have casting numbers? If any valves are bent sometimes they will not close all the way. I have used Cloyes Timing chain sets with no problems. Post back of what you find!