After going to my local Spring shop (which is quite big by the way) and getting an $800 estimate to add 2 springs to my 2012 F350, I am thinking about supersprings. Are they a DIY project ?
I just added a pro comp add a leaf kit for my 2011 F250. It comprised two leafs per side and lifted the rear of the truck about 1" unloaded. Total cost was $500 in San Diego, where labor rates are high. The kit (13150?) was about $180.
I'll be doing a write up soon..
Being that you have a 350 with the taller rear spacer blocks, you might not want the added height, in that case, supersprings.