Don,
I just read this, and was wondering something. I'm always reluctant to give my opinion on some things without knowing all the facts. If this doesn't apply to your car, I'm sorry for waisting your time, but I feel compelled to try and help with a situation like this.
I had a car do this, that's assuming we all had the same death wobble, I put a pan hard bar on it and it never did it again. When you are accelerating you are transferring the weight to the rear of the car, and for some reason this would set it off. The other thing that would set mine off were a double set of rail road tracks.
What was going on in my car was the shackles would allow the front end to move back and forth, once that was stopped the problem went away.
But, our death wobbles may be different.
Ken