Im not doing this as a way to get a cheap lift, i messed up my back shackle and am going to replace it instead of trying to salvage it. I thought while i was spending the money id go ahead and get a longer shackle for temporary height until my next purchase of new springs. Its more of id rather not waste my money on something im gonna replace anyway in a couple of months.
You could probably find a used stock shackle for cheap in the FS section. If only one shackle is buggered up and you want to replace the springs eventually then that's how I would proceed. There's no shame in taking the cheap way out, IMO.