I'm p4etty sure my 62 savoy has a 65 housing in it. Could be a 66/67 too, I haven't bothered to measure. I just know what backspace works on my car. Doesn't mean that what works on mine works on anybody elses.
I had a 65 Coronet that was original and unmolested, but it was sans engine and transmission. It had the original 8 3/4 tapered axle rear under it. 64 was "supposedly" the last year for it, but I have also seen others.