Hi, I am swapping a duel 14 bolt from a 73 c30 into a 87 k20. I have found that the spring hangers need to be the narrow ones. The problem that I'm having is, according to gm parts the hangers for a c30 and k30 are different, and I don't know if the c30 rear springs will work. If anyone has tried any of this, or knows the difference in the hangers, it would really help me out. Thanks,Dave