Hey there,
I just bought a '67 Camaro with a 350 and it has killed 3 different starters (2 of them new) in less than a week.  1st the engine dies, then after restarting what I think is the starter starts screaming and rattling like a cat in a dryer.  Before long the engine dies again and will not restart.  Each starter tested afterward, each dead.  Any idea what could be causing this?  Appreciate any help.
Brian  

Make sure the large negative battery cable is connected to the engine block not the body  

How do the teeth on the flexplate/flywheel look? How do the teeth look on the starter?  

I dont know about brand new starters from the after market but i know that remanufactured starters like you get at NAPA need to be shimmed. If this is the case the starter should come with instructions on how to do so. I have a little experience with this...just a little.  

Yes, your starter needs to be shimmed away from the flywheel. On first start, the drive gear becomes wedged in the flywheel teeth and on restart, the starter is spun at engine rpm. It's not built to do that, hence the screaming noise.