If you had let's say a couple that were clicky and you could pinpoint them you would just take a feeler gauge '.025' and slip/shove it under the rocker at the valve cold fire it up and see if all the sudden they're quiet.
Others try holding a rag over the pushrod side while applying pressure.
Otherwise , next time it ticks at cold start...buy a push rod checker within the range you need, 7" ? turn it off and pull the rockers...check cyl 1,2,7,8 by crankingnthe motor over to closed/back side of the lobe and setting up the adjustable pushrod and the rockers...adjust to zero...then adjust/extend it another full turn, or about .035 or .040 lifter cup depression.
Do all 4 corner cylinders and get an average and compare to what you have ...or order.
