What to do now? It's not an a-body rear end.

So I bought an 8 3/4 rear end 2 months ago from a guy on craigslist who said it was from a dart. I measured the perches at that time and sure enough they were 43 inches. Today, I removed the drum brakes and axles that were leaking. I removed the seals and was cleaning things up when I measured to double check before ordering new seals and axles from Doctor Diff. I have a 741 sure grip.

It measures 56.5 inches. That makes it an E-Body rear that has A-body perch setup.

Has anyone ever used them and just got larger backspacing since the perches are correct? Should I get the axle shortened to ideal size? If so how much will that be to shorten, get new ends welded on to size? Parts would be(100 at dr diff for ends and seals, bolts, nuts).