Front spindles/hubs as I used require dished wheels to match duals on rear. If one uses non-dished wheels on the front, then singles on the rear, then suitable width D-80 axle will have to be found or special wheels made. Not sure if that has answered your question?
Might need to get high gear ratio in your D-80 if using original trans.
Another question answered above might provide additional answers.
Ed
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires. '47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle. '54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed. '55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.