All I have is a 3" leveling kit and my 35's seem to be able to travel all the way up and down... but if you are getting rid of that 3" lift I know a truck that could use one...
I did go looking around for a lift kit and for a 6" that seems like a really good price. I was once offered a lift kit and new 35" tires with rims for something like $5-6000, but those were procomp everything so they werent cheap. take $2000-2500 for the tires and rims out and thats still about $3500 for the lift kit with install. I would check sites like jcwhitney and the more common parts and performance parts web sites to make sure. but rough country are a better known brand so you probably have a good deal there... but like always dont take my word on it
