I have a box off of a two ton truck, I believe a F6, in my rpu. It steeers beautiful. As far as being bigger I think the mounting flange is larger and for getting it to fit into a model A frame I had to reclock the flange. I just cut the flange down till it fit in the frame nice and saved the pieces I cut out,v'd em down and welded em back on to make a repositioned triangle. The metal on those boxes welds very nice wit a wirefeed, I just took my time so as not to overheat it and wreck seals etc. As far as the drag link being longer that worked out to my benefit also as I had to heat it and bend it for clearence on my radius rods which in effect shorten it somewhat. It was all I had at the time and had no way to know how goood it would steer, but figured usually big trucks arent driven as much as pickups as they were usually only used during harvest season. The only regret I have is that I didnt keep the engine from the truck as someone has swapped in a 303 Olds and had a Offenhauser adapter to the ford tranny. So I would say if you have a truck box use it....Weed
