I would like a little more spring clearance, and was thinking of putting a solid spacer between the crossmember and spring pack. I have a Posie's SuperSlider and there's only 3/4 inch clearance between the top of the spring and the frame, giving me only at most 2-3 inches of wheel travel.

I think that if I make a spacer out of solid steel, much as I've seen offered with monoleaf springs, where the spring locater fits a hole in the bottom of the spacer and the spacer has a solid pin to fit the crossmember. The crossmember is more than deep enough to accomodate this, in fact, I have a 1/2" spacer below the spring pack now so the clamp will work, leading me to believe that maybe the crossmember itself is the problem, or I have the wrong spring.

Thanks, you folks are great.
Dorsey