Classic/Antique Car Repair: starter trouble, playing russian roulette, chevy pickup

Question
I have a 48 chevy pickup that has a chevy 235 and a aluminum adapter plate and a 700R4 behind it.  My starter will work excellent sometimes and then others it just clicks and attempts to turn over but won't.  If I then try it several times quickly it will free up and turn over.  So I'm wondering if it is a ground issue since its bolted onto a aluminum adapter plate or if the flywheel could somehow be binding it up by not being completely round?  I did try putting more shims in and didn't make any difference.  So I'm not sure if its ground, switch or starter itself, I did have another solenoid and swapped it out as well but no change once more.  Please help!

Answer
Hi Daniel:
It sound very much like you have worn bushings in the starter. I'm guessing the starter is pretty old? If so the bushings are worn on one side, and when you get pass the bad spot, she kicks over. The clicking sound means you still have some contact...just enough to spin it around a bit to land on a good spot. However, keep in mind, this is like playing Russian Roulette. Once it worn gets to a point where it stops on a spot with no contact, she will be completely dead.

Either have that starter rebuild or put on a new one. That should solve your problem.