Are the rocker arms for the 550 and the 650 the same? Reason for the question is I had 2 rocker arm nuts back all the way off and when I tried to run the stud back down it seems as if the threads at the bottom are dinged. Or do you know what the thread pitch is so I can run a tap through them? Thanks any info is helpful. Oh i do have the 650 cam swap if that makes a difference.
