Prosport not to high jack your post but do small blocks have the same problem, my timing seems to bounce a little ? can this trick be done on the small blocks ? i have play in my shaft up and down, so wouldnt that cause the timing to jump all over being the drive gear could move up and down on the cam gear. i have a rollmaster timing chain and a tensonior on the 416 so it cant be jumping from there. thanks Bondobob