jmckelvy...Yea by using your assumption that the axle is under the center of the bed then I come up with COG about 4" in front of the rear axle. So hope your right, thanks!
I should have stated earlier that that I'm married to a SB gasser truck.
Went by the Chevy dealer today and got their truck camper applications document. They also use a COG range/zone but they recommend it be directly over the rear axle. Took the tape measure to a 3500 Chevy crew cab SB. I realized that I made an assumption that was not true. That is that the COG zone is centered over the axle. It was not on this truck in fact it was shifted about 6" forwards of that. Found the measurements in the glove box to go by. So the Chevy SB appeared to be a a good match for an 840.
Next step is to take trip to big city to measure the mega cab as they don't stock any locally.
