thats cause they are... frames 2" taller on em making them sit 2" higher

 

they say you get about 2.5" out of ford keys i was thinking of taking out my 2" block and put in a 3" and put in a helper spring. Helper spring should 1.5" and the extra inch of the block should level it out.

 

i have 4" blocks been running it for over 1.5 years, now im switching to a AAL due to spring sag caused by the 4" block.

 

What all is needed to do an AAL? We just sold our 2 horse trailer and upgraded to a 3/4 horse trailer. The new one is all Aluminum rather than the steel before, but it is longer and weighs more. The load is balanced really well, with the new longer trailer, and squats less than before, but I'm worried about running it with an addition 3000+ lbs of our combined horse weight. This is on a 2006 ECSB Silverado Z71-5.3 HO.

 

All it is, is an extra leaf the goes between the bottom factory leaf and the lift block, you dont need anything but the leaf the factory ubolts are long enough to accomadate and extra leaf.

 

most of the time new ubolts will come with them though... but like you said factories are good enough