Zbar and Rod ID
It appears to be someone's attempt to modify a z-bar for a big block application. Or maybe something else, but it looks modified to me.
If you go to Brewer's you can see pictures of all the relevant Z-bars here
Brewer's Performance - Mopar A833 4-Speed Transmission and Component Specialists
A-body Slant 6, 8" long
A-body Small block for 10.5" bellhousing, 7" long
A-body Big block for 10.5" bellhousing
Or maybe a modified E-body? E-body z-bar