Hellwig will bend custom bars to your specs, so if you really wanted something stiffer that fit the stock ZQ8 mounting points you could go that route. Keep in mind that the swaybar is just 1 part of the suspension though, I don't know how stiff you'd really want to go without going to a higher spring rate. Too stiff a swaybar with the stock flimsy ZQ8 leafs and you'll just end up lifting the inside tire off the ground on a hard turn.
They don't ride stiffer, they're actually a little more giving if anything. But, after I added the drop shocks and a 2" block, everything stiffened right back up...I still think it rides better than when I had the stock leafs/4" block combo though.
Well, they're bolted together. With my 280lb ass stepping on the pair of Belltechs bolted together they dropped probably 1.5". Leaf springs are progressive though, so determining spring rate this way is kind of pointless. :shrug:
We'll at least be able to get a good idea of which is stiffer though. When I install them in 12-18 months I'll be sure to compare them. :lol: