Third member question HO52 vs 3100 rear end

[66 lwb cs]

I found a third member listed on CL as a 1955-64 chevy 1/2 ton 3:90 drop out was wondering if the third member from that era could fit an HO52 rear end or could it be the ultra rare Randy' s ring and gear aftermarket drop out pic in ad looks similiar to third memer in mine?

[66Submarine]

1/2 ton would have been the smaller HO-33, not the HO-52/72. 4.10:1 HO-52/72's seem to be pretty easy to find, though.