yes
64s are off a 2500HD truck
52s are 4+1 of a 80s 1/2 ton which is little light for my truck, they are literally flat. i have the 52s (6+1 overload is shorter in legnth as well)i pulled off my truck and going to add some leafs to the spring pack. i netted 3.75" suspenion lift over stock.
thing to remeber is the oem fronts are 3" wide and the rears are 2.5". i used 1/4" flat stock and drilled holes to shim then shackles down to 2.5"
this is sitting on it own weight.

ride quality is little rougher then a new 2000-2010 rclb 2500hd truck
i also have the cross over steering vs the oem push/pull setup probly the most expensive part of the whole thing. deffantly worth the money between the 52/64 swap, cross over steering and hydroboost probly the best things i have done thus far. im working on somethign to put a sway bar back in it with quick disconnect when i want to get flexy.