Bolt pattern for a 1985 GMC Sierra Classic 1500 is 6x5.5 (That is what mine is)
6x5.5
6x5.5
6 x 5.5
six on 5.5 chipc@kovach.net
4.52" backspacing -12mm offset 16X7 6 on 139mm bolt pattern
2wd is 5 x 127mm and 4wd is 6 x 139.7mm
8 X 170
6x137.5
6x5.5
8x6.5
5x5