laknox wrote:
A Correct Track suspension mod will give you about 2" lift. Need to be sure that the springs are in the lowest holes of the hangars; if not, move them down and install a wet bolt kit at the same time. Another option for a mild lift (2-3", max) is simply to have longer, heavy-duty, spring hangars made. The couple I've seen on here have also had cross-bracing for extra strength. Short of that, a sub-frame welded between the frame and springs is the only truly safe way to raise it. Steps aren't that expensive, so that really shouldn't be much of a factor.
Lyle
The fiver in question has rubber torsion axles, so a sub-frame is the only lift option. Which is really a better option anyway even for leaf springs. And I agree, steps are not a big deal.
To the OP, Forest River may have a sub-frame type lift kit for the Rockwood/Flagstaf fivers. I had a similar unit yrs ago from another manufacturer and the lift kit was like $175. All it was, was two lengths of rectangular steel tubing and 4 flat steel plates. There is no need for cross members, the torsion axles provide that cross bracing. Any good welding shop can do the work as well. But as other posters have stated, 20 inch tires do not necessarily mean a taller truck bed and clearance may be OK.