Truck wont start. Should I put more shims or what?

Is battery weak?

make sure the batt. terminals are clean and tight as well as any other electric connections and were the starter grounds to the motor , , what ever shims came off should go back on ,

No its a new battery. The shims that came off went right back on and its still doing it. It will work a couple of times then right back to not starting.

Sounds like wiring, solenoid or relay is weak. Check connections like other user suggested. On the relay you have to check resistance also not just "clicking"

Did bad alternator make your battery weak? Test alternator output.

some rebuilds are junk out of the box , try to buy quality parts , it's not always practical though