Of course its possible to put a GAU 8 on a tracked chassis and a rotating turrel. For one thing, the feed system doesnt have to be mounted behind the weapon as it is with the A10. That was done in order to fit it in an aircraft fuselage. On the M163, we had a 2100 rd linkless drum feed which was at the base of the turret, underneath the gunners seat. Probably would want a similar set up for what I propose because of the weight of the drum and ammo, keeping most of the weight as close to the pivot point as possible. Some of the weight and complexity is going to go away because you would not need to cycle fired cases back into the drum-those can be tossed over the side. So far as the weight of the chassis is concerned, you wouldnt need a heavily armored chassis, just one large enough to contain the turret, crew and the feed mechanism. We used a modified M113 and the rear ramp was quite handy for rolling out the belts.