The 3800 and 4100 have very similar frames, same wheel base, frame cross section, etc. You could take a 1-ton pickup bed and put it on a 4100 but I believe the 4400 used a heavier frame with a longer wheelbase. But, that frame could be ordered as a heavy-duty frame on a 4100, RPO xxxx. There may be a short wheelbase 4400 out there somewhere.
