I hope so, it does mount to the frame afterall. I'm guessing that's not what you were asking though.
I'm not familiar with the Roush bar, but if it is just a 4x4 bar it will most likely fit fine. Usually the difference between the 2wd bar and 4wd bar is larger diameter and longer end links. Larger diameter just needs different bushings, and roush should have provided shorter end links. If you don't have end links, again if it's is just a reboxed stock 4wd bar, replacement 2wd endlinks should work.
Actually with a 5" drop you might have to go custom end links if you need shorter than the stock 2wd. Someone may offer replacements for a lowered truck. If I were in that position and they didn't, I'd probably start with some moog replacement endlinks, get a shorter bolt, and shorten the spacer tube.
Where did you get the Roush bar? I don't think they've been available for years.