rough in gear idle and off idle stumble

Shouldn't you ADD clearance when adjusting the valves cold? If the parts expand as they get hot I would think both the valves & the pushrods would get longer, causing the clearances to close up. Being long, narrow parts they would expand more than the cast iron block & head. I thought this was the main reason for having the clearances there. The exhaust valve running hotter than the intake valve is why the exhaust valve has a larger clearance setting, isn't it?