School me in Rocker Shaft Shimming.

I need to do a little valve train geometry correction. The roller on the rocker is a little far out on the valve for my liking at full lift.

Right now my shafts are shimmed with a set of what looks like a tapered, curved washer.

These move the shaft towards the center of the engine and up. These were fine for my last cam but now I need to go a bit more in that direction.

I have been unable to locate this kind of shim.

If you are familiar with these a link would be appreciated so I can finely get this old car back on the road.