99 Ram 2500 with 153,000 and a V10 that all of a sudden starting a tick tick tick noise while running/idling. The noise came on instantly. I immediately did a compression test. High number was 160. Low number was 135. I saw a youtube video that someone had the same ticking noise as my truck engine. He removed the valve cover and a rocker arm bolt had sheared off causing the tick noise.

My question is: Without removing the valve covers to look for broken/loose rocker arm bolts, would the compression test readings tell me what I need to know.
Meaning: wouldn't I get a real low reading if the intake valve can't open and no air is able to enter the cylinder on the piston's downward stroke?