Wondering what these two parts are

I have two other trucks that don’t have either of these

That's the abs pulsator.
Can't you get rid of it? Yes I have and many others have too.

Just remove the abs computer from under the seat, and remove this pulsator, and connect the rubber line to the main line, bleed the brakes.

ABS didn't work all that great anyway on these trucks.

The "newer" B-Series - and not trying to be funny there - had ABS. My 1988 does not.

Cusser Yes I have not see it on 86, 87, 88, or 89. I have on 90 and up.

State Farm Ins. actually gives a discount (safety feature) on my trucks that have the ABS.......kinda funny really!

The ABS light on my B2200 is always lit. Haunting me.