A fundamental of good engine performance is having the valve clearances correct, generally the 4age does not need re-shimming very often so it is worth
doing right.
So yes you do need to check the clearances.
Fairly straightforward to do and the only slight issue is changing the shims with the cams fitted as the edge of the cam follower needs to be depressed
to allow the shim to be removed. (in your case as the head is not fitted you can easily measure the clearances and just remove the cams to change
the shims)
As you already have the head off of the engine then you can do the clearances on the bench, just allow some space under the head face for the valves
to move into. Turn the camshaft until the heel (circular part) of the cam is above the shim and measure the clearance with some feeler gauges.
Make a note of the Valve number and whether it is inlet or exhaust and the clearance.
Do this for all 16 valves.