The Stovebolt Site Forums The Shop Area Driveline Axle perches

Unless you are lowering / raising the height you can just use the stock bottom plate and connect the shocks in the same manner. In that case, the truck and shocks won't know the difference because you won't be changing things by more than a degree or so. If you are lowering the height by 3 inches (as it sounds), that is more than the shock mounting geometry might like. It is all about the angle of operation. You will see GM designed this so the shocks sit at a forward angle of ~33 degrees. I was taught 30 degrees is the optimal range for a pickup. The further you get past 30 degrees is not good because at that point the shock travel is less than the up/down travel of the axle (which you can see would be the same at 90 degrees). With a pickup there are challenges because of varying weight, etc.

Here is my suggestion: using an angle finder app which can easily be put on your cell phone, determine the angle at which your shock absorber will sit after you lower the axle. I think you will exceed 45 degrees and I don't believe that will work.

A friend of mine lowered his (2.5 or 3 inches as I recall) and ended up removing the lowering blocks and going back to stock height because at the lower height the shocks no longer worked correctly and shorter shocks really only repeated the same angular problem for him. What he needed to do was go with shorter shocks and move the frame mount piece to re-establish the original angle.

In my case, I went with stock height and just used the stock bottom plates and had to drill a couple of holes larger since the U bolts were slightly different (because of the diameter of the axle tube). Good luck!