C20 Dually Conversion

[SprayPaint]

I am wanting to convert my 1967 ¾ ton rear axle to dually wheels for my flatbed. I read several threads that discuss this topic and say that no adapter is required as long as I have the smaller 8-lug drums.

So I called southwestwheel.com and ordered one dually wheel to test it out…

(F029587 2000-76 Dual – Base 16x6 8-6.5)

Turns out that the wheel hub hole is maybe 1/32” too small! There is a small shoulder right before the drum where the hub gets slightly larger. The new dually rim just stops short of being able to go up over this shoulder. Other than that, it looks like it would work fine.

Obviously I have the wrong wheel, but where do I get one that fits?

Ideas?

Thanks!!!