Paint marks have no meaning that I know of..........if these are factory cams, 2 V-blocks and a dial indicator on a stand would give you the best/quickest identification.........lobe lift times rocker arm ratio equals valve lift, factory rocker ratio is 1.5.
1964 to 1967 273 2bbl valve lift: .395 intake, .405 exhaust, 240 degrees seat duration "I" and "E"
1965 to 1967 273 4bbl valve lift: .415 intake, .425 exhaust, 248 degrees seat duration "I" and "E"
1968 to 1969 273 all, valve lift: .373intake, .400 exhaust, 240 degrees seat duration "I", and 248 degrees seat duration "E"
Hope this helps.