How much Marvel Mystery Oil per tank?

[Crankster]

For upper cylinder lubrication and valves, valve guides etc, engine vacuum was used with "inverse oilers" like the Ampco unit here, Marvel made them as well. A small metered dose is mixed in with the fuel/air charge. Ampco pointed out that adding Marvel oil to the fuel may dissolve sludge or varnish in the tank and this was a better way.

http://ampcolubes.com/home/benefits