hook ground test lead to engine block then do load test

Will do.
YOU GUYS ARE AWESOME! THANK YOU SO MUCH FOR TAKING THE TIME TO ASSIST ME, MUCH APPRECIATED!
I Have a feeling that my problem is the Spost connection or wire, probably the wire, sin̈ce I sanded clean rhe eyelet clean and the bolts are new. Heat index temperatures are back to 100°+ everyday, so that's not helping, lol.

what are these sensors?
 

They appear Y'd off from rhe Signal wire. Could they have any reason for my click, no crank?
https://cimg5.ibsrv.net/gimg/camarof...3f04a813b9.jpg
https://cimg6.ibsrv.net/gimg/camarof...02c15d82a5.jpg
https://cimg4.ibsrv.net/gimg/camarof...6172ccdaab.jpg
This wire/connection looks sketchy, don't know why it's wrapped in electrical tape, I bought her new, off the lot, original owner. May be my issue?

Do i need these ring washers? They came with the new starter, I pulled them back off thinking it might be preventing a good connection.
https://cimg1.ibsrv.net/gimg/camarof...7b5c2e37e6.jpg

There is a whole lot of tape used in the wiring of these things. I think that's normal.

that's a lock washer, keeps nut from coming lose

WE HAVE JOY!, SHE'S RUNNING AGAIN! But I did nothing new, so I don't trust that it will stay that way.
I charged the battery last week, it had gotten down to 12.3V, still wouldn't crank, even on charger.
Today, I was checking the battery before getting back under the car for volt drop test at starter. Static tested battery @12.48V, when testing under load, engine cranked 6-7 times, only dropped ~1V. Let rest 10 mins ro cool down, cranked another 5 times, while watching oil pressure guage, no problems. Put fuel pump relay back in once pressure reached midline (60psi), she cranked right up, we have joy! But no trust. WTF?! Don't see how I can continue diagnostics when problem no longer exists (unless she strands me)and that'll suck.NOW I'm pulling my hair out, @craby , lol.

sounds like you moved a wire or connection that let it connect

Yeah, but where?, is the delimmma, I still have to put the heat shield back on , so I'll poke around and hope I find something that needs attention. I haven't been back under the car since I charged her last week, but I did test the battery (+) wire to the fuse box, we'll see.

One way to do this would be to unhook the starter, put a test light on the wires, have someone hold the key on start, and wiggle the wires. Bad contact should make the light blink.

Kind of a pain, but might be where you have to go.