The tappets definitely need to be adjusted after the rebuild the new parts will nave slightly different tollerances, if a valve is held open even slightly you will find it difficult to start the engine.
You will also need to re adjust them when you re-torque the cylinder head bolts.
On the T120 engine it is a little tricky to set them, but there are some useful tips on this previous thread.
best of luck
The function of man is to live, not to exist. (Jack London)