Jon, the three rates you listed for A-body front bars are 63-66, 67-72, 73-76 ? Or is that different bar diameters? Are those rates wheel rates or bar rates? I am changing to the 73 K-member on my 70 Swinger, and want to replace my old PST front bar. I don't care for the 73 set-up, because it is about 50% as installed, using the original tabs. I want to get out to my added tabs on the shock mount bolts. (aprox 70%) My current bar is around 340lb installed. Rick, Sacramento.