I hav a deville thought it was a 1973. But they didnt put 500 until 75. The emissions sticker says 501 in big numbers. Was this number on any other engines. The car is in storage about 45 miles away from me. So I dont know if its a 8.* . ? So I cant check the year or the liters. Hope its a 500? Its is going in a 91 sanoma. Wich I just found out today is a 4x4. Now I need to trade this thing for a 2WD s sieries has a 4.3 running. The motor still needs to be connected fuel, wires, etc. the motor is in the truck. The orig plan was to place this 500? in the 91 . cant do that with a 4WD. Can anyone tell me if its easy to swap out the front dif, I have a 400 trans and a 350 trans for the big block orig. Or should I just trade it. Thanks for any tips.