Personnally I've only heard of a couple of balancer pins breaking. I've heard of far more oil pumps spinning on the crank, or cam gears coming loose than I have balancer pins.
As to injectors, do a google search for p0087 and duramax. Almost all of those trucks have injector issues, they just don't want to believeit because the truck still runs good. The problem with 04.5+ trucks is excess fuel return while operating. They don't have the classic issues so much of injector knock, hazing at idle, or smoke. They get the p0087 under load, extended crank time when hot, or just won't start is the more common issues I encountered or read about. Lml's with piezo injectors and cp4's will grenade with just trace amounts of water getting into the system. Or cp4's just go out for the heck of it. I know I checked an lbz that hadperfect balance rated, always started great, no smoke/haze, but everytime he towed in high temps, he would get a p0087. I even ran his balance rates, corrected them, and also ran them with it ramped to 160, and it passed all the tests until he ran an enhanced return rate test, then he found 5 bad injectors. He probably would have never noticed had we not tuned it(small tunes mind you, nothing hot, but just enough to give it some more grunt to help it hold in gear). So many bad injectors go un-noticed simply because the conditions to show the problems aren't met.
