that oil restrictor (as it is known amongst the RB crowd) is useable on ALL RB blocks as far as I'm aware.
But, the diameter of the hole can be from 1/16th to 1/8th and anywhere in between depending on the power output or some other variables that i would have to look in my documents for (i recorded it somewhere)
it also depends on how much oil your pump can move at a certain speed. the JUN pump supposedly flows more than the N1 pump, so you would want the hole to probably be 1/16th, where as the N1 pump would be 3/32ths... which is not quite 1/8th (this is just an example).
YOU CAN make these restrictors yourself from any rod stock that can whitstand heat well (brass seems to be choice), and drill the hole to whatever size you want, or have spec'd out for yourself.
make sure the rod is a touch oversized in diameter, and freeze it for some hours before you plunk it down into the hole. It should require a bit of force to get it into the oriface, even with a frozen restrictor and a room temperature block. but once they're together and both at room temp, the restrictor will be stuck in it's place, even moreso when heat builds up.