I'm pretty sure my new-to-me '04 Duramax (crewcab), 4x4, shortbox has 2" keys, or leveling kit, or something in the front. It sits level, but taller than I want.

Its also rolling on 305/50 on a 20" rim. I like the rims (looks wise), but the extra width in the tires makes it handle like crap and almost impossible to turn at a dead stop. I'm also hoping maybe going back down to approximately stock tire size might make the truck more maneuverable, but then again I'm used to a 2wd, regular cab, it comparison this is almost the Queen Mary in some of the smaller parking lots I have to frequent.



This will be the first time I'll ever have messed with a torsion bar suspension. I know a little about them, but no hard experience.

How do I tell it its aftermarket keys, or just a set of "cranked up" originals?
How would I go about lowering it back down, maybe even lower than stock?
What about that back? Simple dropped shackle or more complex?

I think in a perfect world I would like the front 1-2" lower than stock, then the back dropped to match, with out adversely effecting ride, performance or load/carrying/towing capacity?

I can't speak to aftermarket keys... But, in any case you should be able to jack up the front of the truck and loosen the torsion bar key bolts, to lower the front end. This will help ride some. In the rear, if it doesn't have a block you can either remove the helper spring and bag it for a better ride, or just like you said, add a longer shackle. I don't know what the longer shackle market is like, but you should obviously pay attention to said shackle capacity. You should get an aligment after lowering the front end.

Back when I really dragraced, I'd pull the bolts straight out so that when I launched the cv's would sit in a level plane, rather than downward like in every day driving. That would stuff the 305/17's I had almost into the top of the fender. Sever lack of turning, but yes, you can go really low in the front end without much work.

305's are pretty wide. Both in terms of width AND height, that tire should be too big, as you are aware. The stockers are pretty short, so I'll assume you're looking at rims too? I don't like 20's in general, on a 4x4 truck. Too little sidewall...