As the old-line Chrysler service manager told me back in the 1960s, "All a compression test will tell you is the condition of the top (compression) piston ring". Not the lower rings, just the top one as that is where the basic compression is "sealed". Back then, "leak-down tests" were unheard of except in very high-end shops, plus requiring a good air compressor for an air source.
Another result is that it can indicate if an exhaust valve is beginning to burn, but unless you pull the cyl heads, you won't know WHICH one until it finally gets bad enough to cause a miss on that cyl.
I'm really not sure if "sticking" valves can be an issue on a running engine. If a valve sticks, even with hydraulic lifters, pushrod bending issues might be more prevalent, I suspect. Could be wrong, too.
Consider that if a valve is sticking enough that it takes the valve spring pressure + cyl combustion pressure, together, to close the valve, it's got to be pretty stiff to operate. Plus hard to open, too. At least that's the way it seems to me. NOT to forget about the heat such sticking would result in on that particular valve guide. In other words, something's going to break sooner or later.
A compression check is good to check "cylinder balance". BUT rather than worry about "FSM numbers", consider how close they are to each other. Compression pressure will vary with altitude, too, which can further frustrate getting to "FSM numbers", if that is the goal. You can check the "wear" by putting few squirts of engine oil into the cyl and re-checking. The more difference, the more wear. But ONLY on the compression ring.
You can also do a cylinder balance test by unplugging (Carefully!!!) one spark plug at a time with the engine at idle. Look for the rpm drop each time. Less drops indicate the less-powerful cylinders.
After conversing with the Chrysler service manager, I became less inclined to be worried about compression numbers per se, but more concerned about how they all related to each other. Not a determiner of if the oil rings had any wear on them, either.
If you do purchase a compression tester, get one which screws into the spark plug hole. The other "hold it in place" type probably worked better on inline engines, I suspect, rather than V-8s.
What is your basic concern in desiring to do the compression test?
Enjoy!
CBODY67