Slant Six Hemi!!

I doubt anything at this point in time.

They were most likely producing engines for Chrysler for the South American market back in the day.

The one pictured above appears to be a stock \6 head for the South American market. The only difference I see is the use of studs for the rock arm shaft pedestals and a port for a heater hose on the top of the head next to the thermostat . Also in the other pictures in the link in the first post it appears that someone has worked over the ports.