If the springs are sold as individuals and not in a pack,I am guessing the 220lbs/inch is for the individual spring, i.e., 220 lbs to compress the spring one inch.

I have been impressed with the performance of the 4.3 in Toy's. A buddy of mine runs one in his Toyota Trailblazer, and easily climbs the Sierra's to 7k loaded turning 39's with 5.29's. I think the 4.3 with some mods is a nice balance between performance and weight gain over the 22r. IMO you just don't need the power of a V-8 in the smaller trucks, especially out on the trail, all that extra power usually leads to breakage.