by gregh » Tue Dec 07, 2021 4:39 pm
Nope.
I have a 75 2 + 2 built in Quebec November 1974 and it has a 7.5" diff. The original differential was 256 open rear end that I swapped in a set of S10 axles but then I lucked out and found a 308 posi in the local wreckers and swapped in the whole diff this spring.
Both diffs are absolutely 7.5", I confirm that with the part number on the gear sets.