Violent Take-Off Shudder

Hope to be able to look at it this weekend. I know the pinion is about 5 deg down, will be interesting to see the trans angle.

On my Dart, the factory aluminum bell housing visibly flexed when the clutch pedal was pushed. I’ve been in a couple of other A body manuals that chattered, wonder if that flexing causes chatter. Lakewood scatter shield fixed that, no flex on mine now.