I guess I've owned at least 1 of most generations through the 10th. Many of my heavier duty f series were cusp generations or lagged behind 1 generation. The 1973 f700 I had was actually a 5th gen cab and hood the 1988 F450 was a 7th gen.cab fenders and hood, the 1995 B7700 school bus has the 8th gen.1988 cowl firewall and dash.