Valve spring keepers won't expose.
 

HELP!!!! Having problems with keepers on my LA head. I am trying to remove and replace valve spring on my 72 340 heads. On one valve the spring is compressed but keepers are not exposed. The spring assembly is not dropping down the valve to expose the keepers. I have tried tapping here and there to no effect. HELP!!!!!!

You will need to give it a tap... I would suggest doing that while the spring is seated and with air in the cylinder... :)