'73 bumper brackets on a '76 ?

'74 is an odd ball year.

Early production '74 cars got shock mount bumpers and the frame rails only had 1 hole for mounting the shock mount brackets.

Then, around late December, there was a production issue with the shock mount bumpers. So, late December through the end of the production year the cars got non-shock mount bumpers. But they got all 3 mounting locations, like mine did.

So if you have a '74, check your frame rail. If it was made mid-year on, it should have all 3 mounting locations. If it was August '73 to December it probably only has one.

And that's all for the front only. The 74's all had shock mount rears.
Mine is shock front and rear, but front is only the shock holes.