Others will post lifter-identification techniques. Yes, the lifter is at the bottom of the push rod. What you describe does sound a little like a hydraulic lifter (I misunderstood your first post).
The best ID technique is to pull a lifter and inspect it, but that requires removing the side cover. You might not want to do that is the seal on the side cover is good (no oil leaking out around it).
What is your engine's serial number - it is pressed into the block to the rear of the distributor. That code should indicate hydraulic-lifter or mechanical-lifter.
