Nice lookin rig there @
mrgoodwrench!
Suspension wise it sounds as though you don't really need to do anything for it.
Blocks are alright, just not necessarily the preferred way of lifting a truck.
Sounds like you've got a set of 2" lift springs + a 4" lift block. If you are planning on a shackle flip, you can keep the 2" lift springs and run a 4" shackle flip with their shorter HD shackle. Same thing I'm running on my truck with factory springs.
Blocks are just that, blocks. Technically, they don't increase or decrease the spring rate or change the ride quality. All they do is add space between the spring pack and the spring mounts on the axle. What they do negatively is that the larger the block, the larger the distance, which means that axle wrap and torque on the center pin is increased. Too much axle wrap as well as poor ubolts, and you can spit the blocks right out of there.
Shackle flips maintain the smoother leaf spring rate of a smaller lift pack while allowing the shackle to actually flex and allowing you to swap out shackle lengths to change the lift height. Shackle flips will typically ride smoother than any all-spring lift of the same size.
Factory setup:
Longer shackle = lowering truck
Shorter shackle = lifting truck
ORD Shackle Flip:
Longer shackle = lifting
Shorter = lowering
The factory shackles and bushings have teeth built into them that helps bind it up to increase the weight rating, but makes for a harsher ride.
Go for the greaseable bolts as well, they make a world of difference with the suspension actually moving instead of binding anywhere.
Also, the shackle flip has a tendency to move the axle forward or backwards about an inch... I don't remember which. May or may not cause issues with contacting your rear fenders. If it's an issue, you can run a set of zero rates since they have offset holes to accommodate the change in axle position.