What's the best way to lower my 07 kw9?

You could also look into 22.5 LoPros that will buy you a couple of inches.

 

Good lord, next people will be wanting them to bounce while sitting still. Sorry but I am against any kind of lowering on a truck, and that includes pickups. If you want a low truck by an El Camino or Ranchero. It is the same way I feel about castrating the power in the trucks.

Now a car hauler is a different story, there is a good reason for that truck to be lower to the ground.

 

Seen some freightliners and Pete's extend the fenders to cover the gap. But honestly a work truck doesn't need to be lowered, they made them this height from the factory for a reason.

 

Look up a thread called my little project by slammed379 ... You might pick up useful lowering ideas from him

 

There are many ways to lower your front end. Some good some bad.
I'd start by looking at your front axle, if there's a big spacer block that can be removed. There are many companies that sell air ride front kits. Do a Google. Air ride is nice because you can set your cruising height, dump the air when parked for a really low stance and you can setup an over inflate thingy to push it higher when in rough terrain. Just know messing with height can throw off alignment and camber or caster as well as driveline angles

 

Try letting the air out of the tires that should lower it some!

 

If the look is all your after and not really lowering the chassis. Just have custom fenders put on.