This could absolutely be your starter.... BUT, could be other things too.
When it happens, I would hake a hammer to the starter itself. Give it a few good shots to reseat the Bendix and brushes. If that alone does the trick I'd think it was the starter. In the fusebox, in the cab, there is a relay that is your starter relay it could be that too. There's actually a fuse there too that's for the starter (like 113 - maybe?) Also take a real good look at all the starter connections, wiggle them to be sure they're tight and clean (this all assumes your battery connections are, as you say, good). With the cover off the fusebox use your hand to identify if the clicking is coming from a relay there.
In your previous post, we talked about the NSSW - you eliminated that - right?
The Neutral Safety Switch? Well as you said before, and i think this is what you meant, I tried wiggling the shifter and still wouldn't start, also tried to start in the different gears and still nothing.
Now i know you were helping me before in the other post i had. and that relay problem. Before when this happened and wouldn't start i would unplug the relay and plug it back in and it would start.
Heres the post with those images.
Random relay with wired under steering wheel fuse panel?
The brown wire that was soldered to a fuse, i re routed it to the above relay plug and put a crimp on it and shoved it in there, i would take that brown wire out and put it back in and my truck would start on the days this happened.
BUT, when this happened before there was no clicking noises like there is this time, and i can hear clicking noise this time.
I know there coming from the engine compartment cause i had my ear down to the fuse panel under the steering wheel and heard nothing, and had the hood opened and could hear it quite loudly.
Sooo what are your thoughts on this now...=/