Rear End Question

I removed the axles from my rear end of the '74 Duster last night, so I can replace the wheel bearings. It is a 7.25 with 10" drums with the SBP. I was surprised when I went to remove the axle flange nuts, it was a 5 bolt pattern, and everything I had read I thought said that the 7.25 had a 4 bolt pattern. I have also seen that the 10" brake drums should have been the BBP not the small after '73. Is this rear end from a different year?

The car has front disc brakes with the BBP and the rears were SBP.