Need to know what rear end I have. Doing the okie bushing trick . Got a 1949 3100 chevy. didn't find any dowels on the driveshaft to drill out ,I pulled the front bushing ,no problem still no dowels around rear seal .Plan on driving in an okie bushing and pushing rear seal backward .Is there a serial number on the rear axle to tell me the year ,before I buy the wrong okie bushing .Don't have a mic ' but the front bushing is 1.7?? .Any help greatly appreciated .