i tried that once myself (one auto hub, one manual hub) doesnt work very well, i had a manual hub break and i still had my old auto's so i put one on and tried it. if you left the manual hub in unlock and dont use the 4wd all is good. but when you try and use the 4wd things go wrong, i had locked the manual side, hadnt put the t/c in 4wd yet and the manual side was trying to spin the auto side axleshaft backwards while the hub itself was going forwards, made a loud constant ratcheting sound. ended up having both of the old auto hubs back on until i could afford another set of manual hubs. at least i have a spare manual hub now. i prefer the manual hubs for several reasons, one being i can have 2wd low and back a trailer in using low range but without the front end binding up when turning sharp on a hard surface. auto hubs are pretty pricey to replace anyways. my mile marker hubs were about 180 through autozone. i only broke one from being dumb and trying to back into a snowpile in a parking lot, the rear tires were on snow as the rear bumper started to push, the front axle was on clean pavement. guess the weak link was the hub. just glad i didnt spit out spider gears or twist off a stub shaft.