The first time I over-hauled an engine on a 930 Diesel I thought i did something wrong.
very little oil at the rockers.
All that is needed is enough oil for lube.
If you have 40PSI and oil going to the rockers you should be fine.
The oil in the top groove is for lube of the push rods.
A drop at a time is enough for lube.
Its hard to wrench a problem from behind a screen but it sounds like your ok