Special period wheels?

[factorystock]

This Blazer if from an automotive show in 1970. An era when it was popular to chrome steel wheels. OK, it is a Blazer, rear axle appears to be the standard 1/2 ton axle. Wheels appear to be period 16.5's. Hubcaps are the large 12" caps used only on 8 lug wheels( a trained eye can easily spot this out). My conclusion, these wheels must be 6 lug with a much larger 12" nub spacing, not the typical 10 1/4" nub spacing. I would say these 6 lug 16.5" wheels would be very rare if they accept the 12" 3/4 ton caps.