slant 6 gettin WARM

If it still has a steel shim gasket..

The sand cast holes line up with the sand cast holes in the head. Coolant normally flows back through the block to a point behind #6. It then flows up into the head, and back to the thermostat.

There should be no open coolant passages through the head gasket from the block to the head forward of cylinder #6.

The steel shim head gaskets rust through after time, and short circuit the cooling system.

Voila. Overheat. The coolant must flow to the back of the block prior to entering the head.

Something more to check.

CJ