Is it true that '70-'72 4dr chevelles often came with 12 bolts and more often than not, they were posi? I know that many (almost all) of the '71-'72 4dr chevelles had disk brakes and many of them had air conditioning and tilt wheel! I have seen many '70 chevelles with drum brakes, but '71 and '72 have always had disks from what I have seen (on 4drs that is!) I have never thought to look at the rear end in these cars, but tonight a very good and experienced source told me that most 4 drs came with 12 bolts and many of them are posi's! Does anyone else have similar info?