Blazer Tank Install

[stick72]

I hate to ask this question, I've searched for blazer tank install and come up with dozens of references for putting a blazer tank in a c10. This should be simple, installing a blazer tank in a blazer.

Two straps, 4 bolts, and a tank can't be complicated, but I seem to be missing something. The straps seem too "tall" by about 2 inches. The tank inlet also seems to be located directly behind the body mount.

The bolts on the tank line up perfectly with holes in the frame, but maybe those holes aren't original?

The tank isn't a ebay special, its from one of the vendors on this site, so I'm guessing I'm just way off on the installation, so maybe someone will see something I'm missing.