I have the 55 2nd series which is like your 56.,I went with M2 front suspension.For the rear I took about 4 leaves out of the springs.Flipping the rear is a better idea.I bought a new setup for the rear of mine,but havent installed it yet.I got it from TCI,new 5 leaf springs,mounts,shocks,etc.Also spring perches to flip the rearend.I am planning on installing it this winter.
