The threads in on of my rocker arms is stuck and the nut will not separate from the screw. I replaced the tappet screw and it got really tight towards the top so the threads on the rocker arm must be dirty. It has burned a valve out due to the valve lash being to tight. Long story short I need that part or if anyone can point me to the correct thread pitch Ill just chase the threads and clean them up. Thanks for your time.