Gents,

My names Peter and I am from the uk. I have a 68 Firebird with a 428ci engine. We know through previous ownership that the engine has been in the car 35 plus yrs. Is there anyway of finding out where/when the engine swap may have happened? Could it be a royal bobcat car? If so how do you identify and prove? Any assistance would be greatly appreciated.

The first thing to check is what code, date, and if the motor is a service replacement or not. Does the serial number on the block match the car? I have heard the dealer stamped the service replacement blocks with the cars #. The 2nd thing I would do regardless is to send away for the original paperwork from these guys http://www.phs-online.com/ to find what the car was originally sent to the dealer with and who the original selling dealer was. There were to main dealers that are known for 428 swaps , Myrtle motors and Royal Pontiac but there were others. If the engine checks out with a full size code and a partial serial from one I think the chances are slim to none but by all means I am no expert on these special cars and am only regurgitating what I have read over the years sprinkled with memory loss.

I'm running into the same issue. I own a 69 with the dealer option 428. My dad has owned it since 1970. Mine was purchased through Bob mcglaughlin pontiac in porterville ca.