On a side note, let us know how it rides before and after.
The Bilsteins you're using now will accept the 4-inches of lift? Will they accept the additional down travel? Which shock P/N's are you using?
Bilstein BE52794H3 Shock Absorber
https://www.amazon.com/dp/B004A640JM/?tag=959media-20
Front $49 each on Amazon.
Bilstein (24-188258) 46mm Monotube Shock Absorber
https://www.amazon.com/dp/B009FU78RO/?tag=959media-20
Rear, 79 on Amazon, but for mine for 22/ each on warehouse ??
Monotubes are... Weird. I could never figure out if I liked them or not until now.
I have them on the 88 and on the 11. The key to them is sway bars versus spring rate. Neither is good or bad, but will impact handling.
The 88 has 1750 springs front, moog HD variable rate on the front. Rear has 1" shackle lift. Ttb front with missing bushings on one side running 31s ☠ yes I know I'm dumb.
Were a good move. Truck was bouncy with twin tubes. Never figured out why. Guessing just not enough shock for the spring. Bilstein 4600 front, 5400s rear. Dual front B2 sway bars, one front one rear of front axle, B2 bar with extended links rear.
Very stiff ride, you feel everything. And it's awesome. Truck is very sure footed now, feels very balanced on highway moves at 70+. Top-heavy, but I blame the cap. Much better than twin tubes.
Same deal with the 11, but much bigger before and after. Replaced front 31mm bar and links with moog poly, installed a B2 2wd rear on 276mm links. Bilstein monos front and rear, just shy of bottom out range. Night and day new freaking truck. It's almost grippy now, but tires are bad, so no way to know for sure. If I do the next part right, and increase track width while leveling, I should be able to retain most of the road feel I have with current low center of gravity.
Or not cause I really eyeballed the math.
Bilstein 4600 series will usuay handle 2" of lift, 5400 4" of lift. They were developed for 98-07 trucks, so pre key mod means they're guaranteed to fit. Then shooting the gap with a 2011 pre key, #1 bars, and ??? leaf springs plus rc level should put me close to ride and feel of a leveled fx4 level ii.