GM light trucks were 6 bolt from very early to sometime like the 70's at least - 15's were standard for the 55-9 1/2T trucks, with 16's available for heavier GVW's
"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir "When we tug a single thing on an old truck, we find it falls off" ~ me Some TF series details & TF heater pics
