Any animal supply stores near you? If so a 50 CC horse syringe can be used to CC heads, with a little patience That and a 5x5 inch square of plexiglass or lexan or any clear plastic works with a 1/4 inch hole in it. I use a set of head stands to put the heads in on the bench and then level the heads front to back and cock the head up so the spark plug hole is higher than the cam side of the head and some chassis grease to seal the plastic square to the head to make it hold the rubbing alcohol with food dye in it to CC the chambers
How thick is the outer head bolt bosses on your 516 heads now ?