Rocker Shaft Installation

[scamp340]

I've read that you should place the notch on the rocker shaft to the rear and down on the right side, (the right side as you are sitting in the car). The driver's side notch should face down and to the front. I am doing some work on my 340 today that has 273 adjustable rocker gear and I've noticed that I placed the notch down, and to the rear on the driver's side. The other rocker shaft is placed correctly. I've been running this engine for about 15 years like this. The 273 shafts have banana oil grooves.
What damage have I done, am I losing horsepower? What about oiling issues as a result of this mistake? Would this cause an oil flow restriction?

 

[RedFish]

That rocker shaft is ruined. Rocker arms and spacers too. There are major metal deposits in the engine. You'll need to pull the oil pan, replace the pump. I'd recommend pulling the intake too. There's spots where sludge collects in the galley. New timing set. Might be damage most anywhere and everywhere including the fuel pump. Good luck

 

[scamp340]

Why does this happen. Is it because I've blocked oil flow or something? And if so, to where did I block the flow to?

 

[RedFish]

The oil holes in the head shoud line up with the holes in the shaft. Rockers are oiled through those shafts instead of through the pushrods.