Just installed a new drop kit - swapped out the drop leafs for hangers+shackles, and now the rear is just slighly lower than it was. Also, I just installed the 3.25 pulley, and I'm seeing 9.0 psi at about 3/4 throttle (I know, sounds high - not 100% sure its correct) - and haven't even gone WOT yet because I'm getting some "low pitched" vibration which I think might be the pinion angle (from being lower and more power twisting torquing the rear)

Right now the rear end lines up just about perfect with the driveshaft, and I'm told it is supposed to be pointed down slightly, so when that power hits, it will twist and line up with the d/s. What angle shims do I need? Belltech sells anywhere from 1 to 6deg

 

I know this problem ... I started with 3* I think and ended up going for some spring clamps. I put them in the front which also pulled the rear down some, but it also pointed the pinion up a little too.

As for which degree shim you need ... that depends on how bad your abgle is now.

 

in the end, you want your pinion to be -2* (nose pointing toward the ground)

 

me to... after my flip kit I needed at least a 3* and that's the only one I could find, so I went with it and got rid of 90% of the vibration. Adding shims is a pain in the ***... feels like you are re-doing the whole drop again.


and I can't tell you what shim you need, cuz everyone's truck is different... My advise is to get an angle finder and measure it.

 

thanks for the info - exactly what I need to know