The camshaft cases on the cylinder heads are different.
On non-hydraulyc lifter type there is a removable cover plate
facing upwards, this cam case is in the picture attached
(the cover plate is not shown).
If the cam case is different, you have hydraulic tappets.
Except a few extreme cases, mechanical tappets are usually not get stuck.
(I think the hydraulic tappets aren't stuck too, mostly they wear out,
in some cases along with the camshafts, this results too much clearance,
which makes them noisy. At a fresh engine reassembly they need to self-bleed
the air in order to operate correctly, until this process finished the tappets
are louder than usual, dirung this the clearance will not be eleminated completely)