They don't seem to have the adjustment knob on the bottom. I don't know if the 9-way adjustable will help in your situation, just that it works work in many drag car application. I believe Cal-Tracs use a relabeled or similar versions for their set-ups.
Are you wanting it to spin but stop hopping? Or do you want it to stop hopping and have no spin? I know it sounds like a weird set of questions but there really is a difference in what your trying to accomplish. Describe the intended usage and if it's a low, medium, or high budget. You have a ton of options and will get a ton of opinions. Lets help narrow the field.
Did you torque the U bolt nuts properly? They don't torque incredibly tight so that the springs can actually work. On the A bodies, that torque spec is only 45 LB FT. I don't know what it is on trucks, but the U bolts are the same size. If you over torque them. that will all but stop the springs from working right. Might be worth checking.
Trucks will spin easy because no weight over back wheels. Does it have a pinion snubber? (I don't know if trucks have them).
Forgive me questioning this, but I am not getting this..... the leafs should be clamped solidly together in the center; they are designed to be a solid unit and not move relative to each other in the center. I am not seeing where too much torque will stop the leafs form moving relative to each other beyond the clamping point. Are there some soft spacers in the stack near the center or something?Did you torque the U bolt nuts properly? They don't torque incredibly tight so that the springs can actually work. On the A bodies, that torque spec is only 45 LB FT. I don't know what it is on trucks, but the U bolts are the same size. If you over torque them. that will all but stop the springs from working right. Might be worth checking.
Forgive me questioning this, but I am not getting this..... the leafs should be clamped solidly together in the center; they are designed to be a solid unit and not move relative to each other in the center. I am not seeing where too much torque will stop the leafs form moving relative to each other beyond the clamping point. Are there some soft spacers in the stack near the center or something?