7 1/4 as bad as they say

I agree that there's nothing inherently wrong with the 7¼ rear. Mopar put 'em behind 273 HP with Torqueflites. I had one in a HP '66 Dart with over 300k on it with no problems. I had another on the back of my '73 that ate a bearing last summer with 87k on it. (In fairness to the axle, I think it had been submerged in water.)

As part of converting the Dart to BBP, I'm replacing the SBP 7¼ with a BBP 7¼. I can't get in to measure without taking it apart, but the BBP axle shafts appear to be larger diameter than the SBP shafts. If that's the case, it could account for the disparity of experiences with the axle.