Bat- big cable goes to framerail then on to the RH side of the block by the motor mount.
There is another ground from the head/block to the windshield wiper motor bolt.
There are chassis to frame ground straps visible from underneath, one on the PS bed to frame, don't recall one on the DS.
For systems, the grounds are on the fenders, under the hood. One by (behind) the reservoir set (DS) and another further back toward the hinge, just forward of the brake MC. The PS also has two, both very close to the solenoid, just forward of the fusebox.
There is another on the radiator support, to the DS of Rad.
I believe there are two more, maybe three, located under the cab kick panels.
I'm still taking this 90 apart, so I haven't "found" everything yet.
I have no idea where the radio ground is, but I'd guess either under the dash or kick panel. Did you look for a diagram in the Tech Library? Here's one example:
http://www.therangerstation.com/tech_library/EDiagrams/files/Diagram_radio_typical_1of2.JPG