@#@%# Oil Galley pipe plug!!!!

[The Warden]

Is that the hex looking plug at 7:00 directly below the exhaust manifold flange bolt?

Yes. Later trucks have the hex plug, early ('83 and '84) trucks have a recessed plug that either takes an Allen head or a 1/4" drive; I never figured out which.

 

[Agnem]

Jim, that's it in the picture.