Gear drive

Ran a CAT on a big block 451 and it was fine. Wasnt loud at all, (you can get quiet or loud now) What you do hear is a rrrurrrrurrrurrrurrr with very small fluctuations in RPMs sounding different pitch. ITs not at all annoying to myself, others may object to a solid cam lifter noise too, its all in the ear and how long you've been around rods. CAT tells you to clearance with a piece of newspaper if you are too tight the gears will turn blue with heat when you look at them next (chewing themselves up?) . The do require a close tolerance for the thrust button against the timing cover. Possible hammer time. CAT B/RB is a dual idler so there is a tiny amount of backlash/slop, maybe 1/2 degree, hard to even guess the actual deflection, only seen when you turn the cam left and right on a static motor as the idlers shift back and forth between the thrust sides. WOW, this post is a year old....