I found an excellent variety of shims for the front hubs at Rovers North. That is the only place I found the variety I needed. I don't know if they carry shims for the rocker assembly, but I would look there first.

 

There is nothing exotic about rocker shims. I have made them out of sheet metal before. Just make sure the metal is the thickness of shim you need. Cut out a small piece about the size of the rocker pedestal and drill a hole thru the middle. Viola.

I cannot remember how the Rocker V8 rockers are oiled. If they are oiled thru one of the rocker pedestals, make sure the hole you drill is the same size as the opening on the rocker pedestal. That's how Small Block Dodge's are.

 

So, I'm not understanding how surfacing the head can mean that you need shims. If you've skimmed some material off the underside of the head, you've slightly shortened the distance between the rocker arms and the tappets/lifters. That is, the push rods/tappet assemblies are the same length, but the distances from the bottoms of the tappet bores to the rocker arm cups are now fractionally less. A shim (in the bottom of the tappet bore?) will increase the length of the rod/tappet assembly, which seems to be doing the exact opposite of what you would want to do to offset the effect of skimming the head.

 

Rocker shims are to raise the rocker higher off of the head, in effect gaining back the depth that was cut off of the head.

 

yep, rocker shims are a real thing! Never saw them in one of our engines...maybe in a factory rebuild...

There is a whole procedure for measuring the lifters/rods at all required cam positions....

 

Ah! That makes sense. Thanks for clarifying.
However, shouldn't the hydraulic lifters be able to accommodate the tiny amount of difference without needing to resort to shims?

 

Another need for shims is if the cam is reground for performance reasons, which is uncommon on our rovers.

 

Generally, yes. Depends how much was cut. Last time I had to use any the head was cut .050" and I had to make some .035" shims.

Generally if you have a good machinist, they'll also grind the top of the valve to make up for the amount the head was cut unless you cut it too much.