Can’t tell if you have solid or hydraulic tappets?
With the engine shut down, and any valve closed, loosen its adjuster until its rocker arm “clacks” on the valve stem.
Wait 5 minutes.
Now slowly tighten the adjuster (turn it CW).
Take up the slack until the rocker arm won’t move.
Slowly tighten it another full turn.
If the valve opens, it’s a solid tappet.
If the pushrod goes down (but the valve doesn’t open), it’s a hydraulic tappet.
