The easiest and fastest way to set up the rear springs is to simply measure the difference in the distance between the center pin and forward spring eye centerline on both the stock and 63" springs. If the difference is 7 inches (just for eaxample. Yours may measure different. Mine was 11 inches) Then hang the 63's in the shackles while loosely U-bolted to the axle for the proper width. Set your new hangers loosely on the front spring eyes with the new hardware and raise the assembly to the frame with a floor jack. Just put enough pressure against the frame that you can move the hangers by tapping them with a hammer and that they will stay where you put them. You might want to premark the frame so you have a general idea of where the hagers will end up for that 7 inches forward. Then measure and position the front hangers that 7 inches forward of the stock hanger on the frame. If you have to, you can make a pair of jigs that bolt into the stock spring hanger that will fit against the back side of the spring eye to hold the spring at the desired distance from the stock spring hanger. Then just check that the hangers are even from side to side and tack them on. Make any other measurements/adjustments that will satisfy you in knowing it is right where you want it, remove the springs from the hangers and finish welding it all in. Then finish putting everything back together and cut off the stock spring hanger for good. This will get the axle centered in the wheel well and you may need to figure something out with the shackles if the angle isn't satisfactory. Hope this made any sense at all and you should be able to do this in a weekend without too much trouble.
Just FYI....I removed my fuel tank so I could get a full weld all the way around the hanger. You may need to do the same. I'm sure I don't have to
about welding and gas fumes.
I'm running dual shackles as well on a DD. So, don't believe the hype. 8)
OH!
Also, if you're looking for a cheap way to do a U-bolt flip, I just simply used the stock u-bolts and spring plates from a 1/2T chevy. The U-bolts were the right size for the '88 axle that's in my truck if that's any use to ya.
Good luck and enjoy the build.
