57\" F*rd Rear Spring Q. Can I use these with a shackle flip and a stock or slightly modified shackle on a K30 frame with the shackle flip mounted in it's normal location? I'm getting a K30 shortly, and am wondering if this is as easy as it sounds, or even worth the trouble. It appears others have had good luck with the 57's, are the 56" Chevy leaf packs just as good? Thanks!