Driveline Hitting underside of floor (at rear)

Finally found out what the clunking (techincal term) was making all the noise when shifting from 1st to 2nd (Torqueflite 727). Where the driveline and 3rd member meet at the U-joint appear to be hitting the underside of floor just above teh rear axle. This happens during shifting or when I hit an uneven section in the road that cycles the rear suspension. The car ('69 Barracuda Convertible) has a Dana 60 for a rear axle and is lowered about an 1" using the Hotchkis rear leaf springs from their TVS kit. As I see it, I only have a few options:

1) create clearance in the body so the U-joint/driveline/3rd member don't hit anymore
2) somehow rotate the 3rd member so it points more towards the road and not the car. This would require some angled shims on teh axles
3) Airshocks to lift the body away from the axle. I really don't want to do this as I love the stance of the car as it sits right now.

Anyone got any other ideas I'm not thinking about?

Thanks for the help.