If you have a block style lift in the rear than I feel that even springs clamps isn't enough to keep your pinion angles in check. That block gives your axle that much more leverage on the springs (like a cheater bar) and axle wrap gets worse. Traction bars would work better if you have lift blocks.
Back to spring clamps - go to a chain auto store and buy a universal shackle kit and a drill bit the size of the bolts that come in the kit. Put the bolt in the hole that is by itself on one end of the shackle plate, mark where you need to drill for the other bolt, drill it out, and cut the excess off the plate. Use that as your template for the other 3 plates. When you are done drilling and cutting put a plate on top and bottom of the spring pack and use the bolts from the kit to clamp them together. Quick, easy, and available anywhere 7 days a week. If you have the time it would be a little cheaper to buy the plate steel and bolts seperate but this is a one-stop quick solution.