////worn rocker arms////too much oil flow////suggestion was to add restrictor to oil gallery///

You are talking about limiting the oil flow to the lifters in which the
clearance has increased due to wear. In my humble opinion, you would be
better of to restrict the oil flow to the rocker shafts. The nail thing
involves driving shortened finishing nail heads into the oil ports that feed
oil to the lifters. You could probably use shortened roll pins too. They
would restict the flow rather than block it.

Here is a description of what I did when I rebuilt my 259 V8.
First I tapped the oil hole in the head that leads to the head bolt passage
that carries the oil to the rocker shaft. I used a 3/8-24 tap. The outer
hole I drilled out to accept a 1/4" recessed pipe pipe plug. In the 3/8
tapped hole I put a recessed head set screw ( you can drill the set screw
for any size hole you want. I didn't drill mine at all.
The lifter feed holes I tapped to 8-24 or 32 and put in short set screws
drilled to 1/16". I replaced the stock lifters with mechanical AMC lifters.
These have a piddle valve and must be used with hollow pushrods.The hollow 
5/16" push rods I got from Crane as they are a custom length. I replaced the
stock rocker arms with shaft mounted roller rockers. They are now lubricated
from the lifters and hollow push rods. If I were going to do it again I
would plug off all the holes in the rocker shaft too since they are not
necessary now. This combination will limit the amount of oil sent to the top
of the engine and keep it in the bottom of the engine. I also built and
installed a windage tray using a tray I mounted to the main caps and the oil
pan. The main cap bolts can be replaced with Chevy Big Block windage tray
bolts, at least the ones that would be located over the sump. These bolts
are much easier to find than the R3 windage tray bolts and are less
expensive.

Paul