Hello most knowledgable ones, I recently installed a 4" lift kit on my 87 Jimmy consisting of tuff country springs in front and ORD shackle flip in the rear with an add-a-leaf. I had terrible vibrations in the driveline until I lowered the t-case. I still have vibes at about 40 to 55 mph. under load only. It seems as though my rear diff. is in a staight line with my driveline with a severe angle at the t-case. I know I should probably lengthen the d-shaft,but should I consider a cv system since the diff and d-shaft line up? I don't mind spending the money if it corrects my problem. I've heard that the cv joint fails often. Is this true? Should I upgrade too 1 ton units? Any advice would be greatly appreciated from all you guru's. Thanks in advance, Chris So addicted it's not EVEN funny!!!!