1995 Chevy Suburban Front differintial

From your description, it sounds like your front differential went "belly up". You can check it by putting the transfer case in neutral and turning your forward drive shaft. If it moves more than about 10 degrees, it's pretty had. To change the truck to a solid axle unit, your talking a major remodel. Suspension, steering, driveshaft, brakes, everything. With 280K on the truck, it would have to be a real cream puff to even consider it. You'd be money ahead buying another running chasis and mounting your body on it. This would be easier. Hope this helps.