Franken, when I was researching what to build someone on here did something like that.
http://67-72chevytrucks.com/vboard/s...77&postcount=7
Except it looks like they used something thicker than exhaust tubing. I considered doing something like this because I have a bender with a die for 1 1/2" pipe.
I really wish I had done tabs that overhang the top of the tubes for the bolts(like in the design linked). It was a small pain getting the bolts in mine up the tubes and into the holes. I might modify mine.
Landarts, it looks like your plans call for .095 wall tubing which is thicker than the 14ga(.0747) that I used. I guess that works better for your 1.75 sleeve. I would be careful with the placement of your wheels. To make sure it is easy to tip. My wheels at the front are positioned behind where the cab is mounted. I was also working with mine a few times this week and you can see I actually have the parts that are designated at 57 inches long on the plans left longer(taller) and I seem to relay on that extra length when I'm flipping to keep it from slamming on the ground or wheels. So... it might be advisable to keep them longer.