I would appreciate if someone would explain the "Proper" workings of the hydraulic lifters located in the rockers. I'm installing new ones, so I know I should pre-load with oil. Should they be stiff with no give after loading? Do they "give or compress" somewhat while opening the related valves. Also describe proper way to pre-oil. I hope the tiny little ball in the bottom end has something to do with it. I think I'm filling them ok, just wondering if they should have any give to them as they do before oiling. In engine operation, surely the oil cycles in and out of them somehow. Please explain. Thanks.....