rear bumper brackets for a 67 with leaf springs

[hpcgmc]

So... the vender tells me he is certain these fit, and that maybe my frame was not drilled for sport bumper brackets. But after looking at this closely, I'm pretty sure he made a mistake and had the wrong hole drilled.

If anyone has a set of these laying around, or can get to the mounting brackets on their leaf spring 2x4 truck, can you tell me if the distance between the two mounting bolts is 5 1/2" or 7 1/4"? On my truck frame, the difference is 5 1/2". That also seems to be the correct distance needed for the outer brackets to line up correctly.

I'll be drilling out the second hole when I get to a friends shop next week to see if that's the problem, but probably wont be using this vendor again.