HELLO i HAVE A BBC THAT I WAS WANTING TO FIND OUT JUST EXACTLY IT WAS. I HAVE THE NUMBERS OFF THE BLOCK AND HEADS . THE PAD IN FRONT OF THE PASSENGER SIDE HEAD READS=T1001TRW C4B116871 ON THE BACK OF THE BLOCK IT READS 999289 T12 DRIVERS SIDE HEAD READS 12673 GM11T PASS 336781 PASSENGER SIDE HEAD READS 338781 GM9T 12773 . IF SOMEONE CAN HELP ME OUT I WOULD GREATLY APPRECIATE IT.