Yes, that is the casting hole plug. But, it is not a standard (freeze plug) and must be set in a special manner. My suggestion is to use one of the common parts vendors to purchase the correct plug. Install convex out, set with ball peen hammer by indenting center of plug disk. Sealant around edges prior to installing is good idea as well.
Last edited by DavidF; 12/02/2013 8:37 PM.
