Love the custom tool boxes on the flat bed.
One thing that I;ll point out about the frames on our Ford trucks that became evident early on in the 70's was the ability of the frames to flex in off camber rough situations. Ford trucks became well known for this and the chebby trucks became just the opposite. I've seen so...many C-series trucks with broken frames, (because they were never designed to twist like our Ford trucks were). The C-series had an even worse issue with frame cracking due to the wimpy suspension / steering geometry design causing cracked frames at one of the most critical area's on the truck-behind the steering box.
Only mentioned the above for thought to the possibility of adding too much beef, (additional crossmembers) to the frame that could possibly stop it from flexing?
Keep up the good work!
