Just to note for some people to save time and a good chunk of money.
I ended up replacing the battery thinking there was a battery manufacturing defect.
It was not the battery.
I then ended up changing the alternator, thinking it was a voltage drop from bad bearings.
It was not the alternator.
Soon after the alternator replacement the starter was on and off clicking when trying to start and so I thought, well the starter has been going bad and the solenoid is no good.
So a new starter.
And still having the same troubles.
My cousin being a modern auto mechanic said for just S&G try going out and getting a $5 negative lead which connects from the battery to the actual block and see if that helps.
New $5 cable and it starts, amps are solid at 14.5ish starter turns over and everything is great.
The cables on this model (mine is a 1988 Chevrolet K2500 5.7L) for the negative lead to the block can burn out and it will not show any ware or burning. The cable just fries internally and has a slight or no connection at all.
This would have saved me $300 easy if I would have just tested that out.
The amazing part is I also tested the voltage and amperage off the battery to the different positions and they were all within starting specs, but when starting the engine turning over and moving just slightly it would shake the connection loose and break the power.
Sad ending to the story also was the new alternator ended up burning out the bearings right away and I had to get a second replacement, free which helped.
I hope this helps.