Joe H, thanks for the link. I have seen that book somewhere before (probably here) but need to remember that it exists. As typically happens the book dimensions for the 3600 are with differnet size tires than I have but I think there are enough dimensions that I can calculate the numbers for my configuration.
fixite7, thanks for the eyeball insight. I do not have a nice digital protractor like the videos like to use, just a carpenter's protractor and a bubble level but I would like to believe I can get within one degree.
Jon G, thanks for the insight regarding axle wrap, a heavy load start probably puts a lot of torque load into the equation given that there will not be any wheel spin.
I tried my trick of putting the chassis on the lift with jack stands under the rear axle to load it. Unfortunately moving the front of the truck up/down changes the chassis angle so fine tuning the setup may be a bigger challenge than I was hoping. I did measure about a 1 degree change from totally unloaded to chassis weight loaded rear springs. Without doing the math suggested by Joe H I suspect that adding the rest of the truck metal and wood bed will probably move it another degree or two. If that holds true I think I will add 2 degrees to the engine/transmission (currently reading 2 rather than 3 degrees) for a pinion angle of 4 degrees.
I also made a rough initial measurement for my drive shaft and from the tail of the NV3500 to the U-joint on the rear axle it is roughly 62 3/4" long and runs downhill at a 10 degree angle.
