First, now days you here a lot of talk about needing to get flow to the top of the engine quickly. This talk is all about overhead cam engines. Some of the engines are aluminum heads and there is no bearing. The head just has a half round cut into it and the caps bolt to it. The only thing between the cam and the aluminum head is
oil. If you do not get
oil flowing to the cam quickly on a cold start, its a train wreck.
Push-rod engines do not apply to all of that talk.
Bottom line, as far as springs and valve guides go,
oil flow nor oil pressure is critical in this area. In fact they use to put umbrella type valve stem seals on the valve stem to prevent too much oil from getting on the valve stem and dragging past the old cup type seals. You don't need a lot of oil going to the guides. If fact too much will cause it to burn the excess oil. The springs don't do much rubbing against anything, unless the rpms are so high that they are gyrating all over the place. Well the seat and cap see movement. Again if oil pools up, there is plenty. You just need flow to carry away some heat.
If you are getting oil out of every push rod, odds are you have plenty of oil flow.
I tend to be on the side of thinner oil in most engines. A small block does not need thick oil unless the bearing clearances are looser than I would choose to have. I run 10W 30W oil in my 5.0 / 347 stroker.