Thanks for the suggestions. It sounds like there are 4 items I need to check:

Battery - It's reading 11.97 volts. I get the clicking sound from the relay. I put my battery charger booster on it with same result. I swapped the battery out with the one from my Galaxie / reads 12+ volts. Same result.

Relay - The voltages at the battery lug are the same I'm getting off the battery itself. Same for the starter lug. I will go back and check this one again just to make sure. I'll also try and short the battery lug to the starter lug but my guess is if the reading is the same on both sides, the result will be the same.

Starter cable - I initially checked this but I need to pull it and clean both ends again and make sure I've got a good connection. Seems like I had voltage to the starter but I will recheck.

Starter - I can pull it and take it to the parts house and have it tested. I thought it was good but in hindsight have no basis for that assumption.

Is there anything else in this chain I should examine or revisit? Thanks again.