E30 Zone

hey
I reciently swoped my cylinder head. New belts and gasket now when i get the car going its not ideling right. A local guy told me that the tappets and valves need set for the new block.
Its a m20 engine and its a rattle and slight knock sounding from top end. What im asking has this happened to any one from here and is it what he says?

Do your valve clearances as a matter of course
m20s can be a bit 'ticky' up top anyway. Knocking noise though could be another issue

Your erratic idle could be an air leak in the intake system,OR has the battery been off for a while? (engine will run a bit lumpy while the ECU learns its new settings)