what to do wheel will not fit

A '67 B-body rear axle housing should be 54 1/4" flange to flange, not 53". If it's 53" it's been shortened.

The axle flange offset is different as well though for the BBP axles compared to the SBP axles, so, the BBP axle/brake combo does have a wider track compared to even the same width housing with SBP axles/brakes. Sounds like you're going to need rims with more backspacing regardless.