Ok - I started the car - starter kept freewheeling while engine was running - turned key to off position engine kept running and starter kept spinning, I had to pull 12v coil wire and disconnect battery to quiet things down. Can a bad starter solenoid cause this? If not where do I look? Thanks team.

1969 Camaro 350/350

It appears it's time to get down and dirty and replace that starter!....Most likely the spring or the bendix drive within the starter motor cracked, it's not releasing!

Yes a bad solenoid can do it as well as starter mechanical failure as mentioned by badbird. Starter drive retainer may have broken allowing drive to ride over retainer clip getting drive stuck in forward position. It sounds as if solenoid is bad, but be careful. If you started the car on a low battery the contacts in the sol may have arcked causing the contacts to stick together. If that is what happened you will have to find the cause of the low battery or it may happen again.