Johnny -- Be sure to check out our Tech Tips and Links (see the menu bar at the top of the page) -- Lots of info there for you and your truck.
I'm about 90 percent through a frame off resto of a '49 4400 and I also have a '49 3800 -- the cabs, doors and interiors are identical except for slight difference in how the headliner goes in -- but that's because one truck is the early '49 and the other is the late '49.
The other sheet metal (hood, fenders, grill, inner fenders, splash panel, etc) is different from the smaller trucks -- mainly bigger to accommodate the bigger tires.
Good luck with your project -- ask lots of questions, or make observations -- that's what we're here for.
Regards,
John
