I thought this subject was covered elsewhere, but I looked a bit and couldn't find it. Feel free to slap me and point me to it if it is out there...

I've seen that the frames for most of the boxes are made with 2x2 and 2x3 square tubing. What wall thickness is normally used? I was thinking using .090 wall - much less than that starts to seem flimsy, and much more than that is going to start getting heavy. Any opinions or experience?

How are most of the frames tied to the truck frame? Are the floor joists just bolted to the top of the frame rails? Is there a subframe that's bolted or welded to the truck frame, then then box floor is attached to this?

I saw an ad somewhere recently that was a truck that Kingsley had started a conversion on but the owner lost interest. It had a subframe but no box. I can't remember the exact size, but it seemed like the subframe was huge - like 4x4 1/4" wall tubing. This seems excessive to me, but maybe not.

Comments and advice?

Perry

It pretty much determines the layout of your conversion, for instance, I used a 4x4x.25 tube and then sandwiched a piece of rubber between the tube and the frame of the truck and then u-bolted it down. On top of the 4'' tube I ran 2x3x.188 rectangular tube 16''o.c. Maybe a little heavy but I don't want the rattle and all the twisting associated with cheaper built units. I also have 3 large slide outs which decreases my wall strength, so by adding strengh to the floor and the roof, I can justify these slides. Also the more weight you put on these trucks the better your braking and ride will be, try bob tailing one and then driving a loaded one, see which one handles better. Take a look at my gallery and see if it helps

From looking at your gallery... It looks like you have 2x2 verticals on the walls with 2x3 cross bracing between them? Did you put that many cross braces because of the big holes for the slides - do they normally put in that many?