I'd suggest you investigate the dimensions of the 3600, 3800, and 4100 frames. Each is incrementally a little bigger and thicker
Yes and no, there is no significant difference in the 3800 and 4100 frame. Best I can tell the 4100 is just longer on the front to mount the bumper differently than the 1 ton that has a different bumper and brackets.
It all depends what you are trying to do. I feel that the original frame choices are good ones, and they will be the least amount of work to use, they also look right if you care about that (I do for my truck). I considered a frame swap, and now that I am done with my frame modifications I still think I made the right decision to use the old frame. My truck will be an every day driver, taken on long trips, some really long, and regularly haul heavy things.
Grigg
