So yes, the 75F, 76F, 77K, 78K can all be used. The 78K head if complete will have different valve collars and the valves will differ only in the cut for the collars. The 78K head if complete will have the stronger springs found in the 77F and 78F. If the 78K head is bare you can use any of the valves and collars other than the 77F and 78F.