340 motor pumping excess oil on right side

Oil accumulated at the top end of a LA small block is pretty Normal, especially with a Hv oil pump. That’s why many racers will restrict it will a tapped plug, and a smaller hole drilled in it.
Usually I’ve found it to not be a problem.
Excessive vacuum seems to be a by product of more modern cam profiles, and in conjunction with an oily top end and loose valve guides is a recipe for fouled plugs.
I recently went through the right side head of an engine I built, but didn’t put the heads together, constantly fouling the back two cylinders 6 and 8
I was in denial about the heads, and pulled the engine to inspect after 3,000 miles.
Put it back together new file fit rings, Cometic head gaskets, upped the compression a little, same thing maybe worse.
This time tore the heads apart to find the guides all loose, and pc seals couldn’t deal with it.
The point is, it pulled oil more heavily down the right side, and only fouled the two rear most plugs.
I bought a pro form valve spring removal tool, and double check my cylinder head guy, as he did it again on some W2s I just wrapped up, only to redo the valve job he just did and put new guides in after picking them up. I had to fire him.