Thanks for the friendly words, I now have 3 out of the four replaced, will replace the 4th next month and the spare after that, I just spent a ton of money on the TV getting injectors and all new brakes, rotors and calipers, so one thing at a time. The dealer has very good prices and he was not being a jerk about it, he was just being informative. I always stuck pretty close to the 6.5 to 7 year change, but I guess like everything else, will have to keep a closer eye on them after about 4 years.
03 Silverado cclb 3500 drw, D/A, Reese 22k hitch
07 Alfa SeeYa Gold 30RL,2 slides,power everything