I have done some research on the 15 X 6 Rally Wheels. I pretty sure the correct 15 X 6 Rally's for a '67 Z/28 were coded DF. I have 3, not a matched set, that are coded DC as follows: K17 12 (stem) 7 DC
K18 4 (stem) 24 DC
K18 8 (stem) 20 DC
From research I have done I believe that the first Wheel codes out, Dec. 7 -67. #2 Wheel I believe is Apr. 24 -68. #3 Wheel Aug. 20 -68. I have found information that the 15 X 6 DC code was used on Corvettes in '66 & '67, but I believe that Corvette went to 15 X 8 Wheels in '68, which these wheels code out to be. Anybody have any ideas? Thanks!