Can someone help me identify these heads, there is none of the usual casting numbers near the exhaust port, just 'ECL" in the intake port. The only other numbers are stamped "64077" near the spark plug. They came off a Australian 61 F100 so probably Canadian origin but not shore. I have a couple of pair of "ECZ" and they don't have the "knob" at the plug hole

Pete, one of the Aussie mob. Beechworth, Victoria60 F100 Panel Van, Y-block. 65 Galaxie Country Sedan 390