BBP 7 1/4 axle shafts

If your existing housing had 9" brakes LBP shafts will not fit. The 9" housing was wider. I'm pretty sure all LBP 7 1/4 rears had 10" brakes (SBP 9" drums went away after 73 I think). The 7 1/4 was used through 76 as the standard rear end for /6 and 318 auto cars. If the Sure-Grip option was ordered I believe the 8 1/4 was fitted to the later cars, even /6.