Don't know how far you moved your springs, but for the 3/4 inch shift (see offset shackles) all it took was a longer bolt for the hanger and a wad of fender washers (wide to make it stiff).
By the way, these are the "right" tips for your car - long box, short bullet - designed for 1970 340 Swinger, so one year only. There used to be a company that made them out of stainless with any inlet, but they went out of business. Been searching for a new source for years. Long bullet, short box are for A-bodies with no valance, just a bumper.