[Jacques Reed]

Thanks, guys, for all the replies.

Great to finally know where the round plates were used. Now the only question is why they were on a truck without a heating/defrosting system. There were no holes in the engine cover that needed a cover plate.

The rods may have been "borrowed" from another truck based on the good information supplied. Only speculation, but perhaps to steady an air cleaner?
My first truck had a piece of flat bar bolted to the intake manifold then attached to a bolt brazed to the air cleaner. All because the original carby clamp was missing. Those rods would just about do the same job.

Cheers,