The biggest issue IMO is that there aren't any choices for higher capacity AHC torsion bars. There was a thread on here recently where someone talked about getting some custom made that would hopefully split the difference between the light AHC bars and the relatively heavy non-AHC bars.
Personally, I didn't think the kings were a bad thing with an empty truck: noticeably stiffer without being anywhere near stiff.
I've slowly made my way up this table through literally every spring here, and just installed the 80 LC springs yesterday. They've done a pretty good job balancing my too-stiff t-bars. I also set my front AHC pressure at the low end of the spec to help keep the stiffness down. Adding the LC rear springs forced me to lift the whole truck an inch or so to get the rear AHC pressure to the right spot, followed by cranking the front and adjusting the sensors to level the truck.
I've got a list somewhere, but spring rates that 'work' with AHC are as follows (from memory....):
Stock AHC 100 series springs | 90 lbs/in |
King KTRS-79 | 130 lbs/in |
LX450 Rear Springs | 150 lbs/in |
80 series LC Rear Springs | 170 lbs/in |