It's possible the Load Levelers were added to compensate for weak springs. I'd suggest putting the truck back on the ground after unbolting the aftermarket shocks to see where the ride height goes without the added lift of the coil-over shocks. It might be necessary to install new springs as well. Another option would be conventional shocks and aftermarket air bags that fit inside the springs. They're adjustable to compensate for load by simply adding/removing a little air, and they don't require the high pressure air source a set of Hijacker air shocks do.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!