With accurate measurements and some basic metal fabricating and welding skills, those Brownie mounting crossmembers can be built on the workbench and all that's needed to be done on the truck is drilling a few bolt holes in the frame - - - - -the vertical part, NOT THE FLANGES! Then give a driveshaft fabricator some accurate length measurements and let him figure out how to build and balance both shafts. Dana/Spicer has an excellent tutorial on setting up multi-piece driveshafts, and I believe it's available on a website somewhere.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!