Rear U-joint hitting the floor on 67 Firebird
 

I have been beating the hell out of my floor over the rear U-joint. The bumpers over the axles were shot so I replaced them but destroyed the one over the pinion. I'm getting another one to try again.
I'm running a moser 12 bolt with 1350 u-joints and new multi leaf springs.
Are any of you running traction bars? If so what kind.

Wow your really deflecting the hell out of your leafs. I can't tell how far your pinion is from the floor but it looks pretty close.

I think a set of traction bars or caltrac traction bars should be on your Christmas list.

I'll have to jack the car up to know for sure but you're right about it being close. Apparently my tires have better traction then I thought. :)

Well I'm happy to report that the traction bars made all the difference in the world. No more hitting.
I went with a pair of Lakewoods http://www.jegs.com/i/Lakewood/620/21606/10002/-1 The only thing I may have to do is shim the fronts down a little. There is no gap between the springs and the bumper.