If you do pull the head (the best call by the way) turn the head on its side with the intake and exhaust ports pointing up. Pour solvent or rubbing alcohol into each of the ports, one port at a time. Look in the valve side of the head and combustion chamber. If you have solvent leaking past the valves, especially the intake valves, you likely have bent the valves and will need to replace the bent valves, and have the seats and valve faces touched up. Not a terrible job. More time consuming then anything else.
