We have an 880 on our 2003 dually. We needed to build a cradle to lift it approximately 3" for clearance. Some go shorter, I felt like this was better.
I just posted details on our (crude) cradle. If I can find it, I'll post a link.
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/27170413/gotomsg/27180487.cfm#27180487
We did add Firestone air bags to help with leveling out the load, as it was a little nose-light when fully loaded. Also added Tok-lift Stable-loads to engage the overload springs a little more efficiently. I heavier rear sway bar and Bilstein shocks were a plus, too.
Other than that, we love our 880 and it works dandy on the tuck.