[vettestr]

Well the good news is if one needs adjusting they all get done. A solid tappet engine as you know has lash or say 0.024" clearance between the rocker and the valve tip/lash cap measured hot. Your cam card will tell you the exact desired lash.

At 11K miles they could have just gotten noisy enough that you just noticed them. If you are not comfortable doing this alone for the first time in a few years it might be worth a helping hand from a gear-head buddy.