I recently purchased an 85 Monte SS. I believe that the motor is not the original 305 because the valve covers have the bolts across the center not around the perimeter. From what I can tell its an 87 or newer. The numbers stamped on the block in front of the passenger side head are (CC 5 174). Can anyone tell me what motor I have? And does anyone have a good website to go to to determine this? Any help would be appreciated, thanks