Trans is in.

Cliff it's real hard to tell from the video and it doing it in neutral worse is really odd but pulling the access cover would be the 1st thing I'd do too. Look for shiny marks like Green said. If something is rubbing it'll shine things up real good. If you don't find a problem leave the access cover off and put the starter back on and try it and see if it still does it.

btw: I assume you used the correct torque converter bolts? Standard 5/16" bolts have a thicker head than the original converter bolts and can hit the access cover.