Late model Chevrolet stuff also doesn't have the hubcap nubs. Check this out: http://www.ackerwheels.com/wheels/AW1619.html
Looks like 1988-2002 is the era for them.


Some of my crap:
1963 C-30 flatbed dually 292/SM420
1965 C-10 LWB fleet 250/column shift 3 speed
1965 C-30 9' stepside 250/SM420/4.10 gears (my DD)

Website I made for my crap:
http://www.66submarine.com