I think 6bblgt is correct in stating that on B and E body's with either H.D. sups., HD brakes, or disc brakes got the 6" steel wheels unless you ordered the Rallye or Road wheels. I was incorrect in stating that there were four different 1971 B - body tires that got the 6" rim as std. I think that only the G70 x 14 got the 6" rim as std., but I found a side note stating that G70 x 14 tires required HD susp. So now I think that accounts for all 6" rims end up getting HD brakes or disc.