If I have the engine out of my car, and have seated the torque converter on the input shaft of a small block 727, how much "wiggle" should I get if i push on it near the edge of the flywheel? should it move at all? if it is seated, should it sag so the teeth are almost touching the bottom of the trans case?

Just trying to guage if i have a bad converter... was getting some heavy vibrations from it at around 55mph.

TCI 11" breakaway with 2400rpm stall if you'rre wondering.

The movement you are feeling is more indicitive of a worn front pump bushing than a convertor issue... If you don't like your TCI vert just throw it my way...

If it's seated all the way back it will have a tad of wiggle. If it is not fully seated all the way back it will have a lot of wiggle. First question on vibration is your converter flex plate weighted? When a weighted flex plate is used in non weighted application and visa versa you will get a terrible vibration. Make sure your flex plate is matched to your application.