I'm second guessing myself or am I?
 

I set the adjustable lifters on my "66 with 326 HO. and am second guessing that I (77 years old) did them all correctly. Is there a quick way to check all of this?

Factory bottle neck studs and nuts or adjustable poly lock/crimped nuts?

Adjustable polylocks. I finally ended up buying rocker arm oil deflecting clips and adjusted with the engine running. So glad that I did because now I feel that they are correctly adjusted.

I agree. Set the hydraulic lifters with the engine running.

Very simple--adust the rocker nut until you hear clicking from that valve, then adjust the nut about 1/2 to 3/4 turn beyond where the noise stops. Lock the nut at that setting.

Another way if you don't have the clips is to cut a slot down the center of an old valve cover and adjust the rockers with a socket and extension through the slot.