Hi, can anyone clarify for me the different types of cvh rockers and what should be used where?
My old engine book says there were two types,
Two holes for hydraulic lifters
One hole at front for solid lifters.

The issue is I have just changed the camshaft on my Efi engine and the ones that are on there were bought new a good few years from ford but don't have any holes.
Plus on this engine I have a very annoying metallic tapping still, which seems to appear more once engine is warm. Now racking brains if this rockers , worn valve guide, loose valve seat or broken piston ring.

Any views?
Dave