Ok.... I have two Delco coils.... 270 BR and 270 B-R. I read that the BR is for 68 and B-R is for 69. The BR is the original coil to the car.....not B-R. 69 SS 350 with cowl induction O6A build. Can anyone clarify why the disparity and what’s the difference between them? I know that the BR means ballast resistor, but why the difference? Was there a manufacturing change, etc???