Lifters and distributors (gears) should always match the cam.
Later cams, lifters and distributors are made from different metal than earlier ones. Any mismatch and premature wear can occur.
It's possible that your engine was rebuilt at least once and you can't always be sure what cam and if the correct matching lifters and distributor were used.
There is a way how to identify early solid and hydraulic cams, by looking at them with the oil pan removed.
Not sure if the same method can be used to identify later already installed solid and hydraulic cams.
Hydraulic lifters on a solid cam are less of a problem than the other way around.
Solid cams have gradually raising and lowering 'ramps' to ease the cam lobes against the lifters and their valve lash.
Hydraulic cams have a much faster valve lift than solids.
Hydraulic lifters need to be replaced eventually, as old and worn ones can collapse and cause a lot of noise at the rockers and lose power.
If you tightened them to spec (1-1/2 turn after clicking stops) and you still get valve lash clicking, it's best to replace them.
