My truck has the typical self-lowering front end, and while it would be easy enough to replace the spring spacers while I have the front end apart for a rebuild I decided I'd rather lower the rear than raise the front so...
Seemed easy enough, go to the parts store and buy the 13-4100 shackles fight some rusty bolts and yeah... no. Seems they have changed the design of the bushing and you can no longer just press out the metal liner and stick the factory bolt into the bushing - You will press the urethane bushing out of the shackle before that inner sleeve comes loose believe me I tried
I'm not quite ready to start drilling rivets out of the frame so I guess I'm going to have to cut and extend a set of factory shackles. If it was easy everyone would do it, right?