Can anyone tell me how to tell if a torque converter I have on the shelf is the factory one or aftermarket. It is about 10.5 with 7/16 bolts to the flex plate. I still have the 8 bolt flex plate and the holes on converter are same spacing.I switched my 67 GTX to a 4 speed years and years ago.Trans gone but I kept this.Have not found any numbers or stamping on it.