Question I have changed valve springs before with the compressed air method but was thinking since I'm going to change all of mine would it be easier to just pull the heads and change them? The motor is already taken apart to a long block. It has 47k miles would I have to have the heads resurfaced? Or can I just clean them up like any other gasket surface?

 

You would just have to clean them up and check for straightness if you took them off.
I have changed a few sets on the engine and just put the piston at tdc on the cylinder I was working on without issues. I never tried compressed air.