OK, boys, need some help here... This rearend is in a '36 Dodge 5window coupe. I have a feeling that its the original, but just want another opinion (or two) Thanks!
It has the slip joint instead of U-joints and the drums are on a taper with a key-way/castle nut (i would post a picture, but don't think i have one.)
See how the pinion shaft is in line with the axle shafts, not below them as in modern hypoid gearsets? That makes it an older unit, prewar. The ball-and-trunnion U-joints and tapered axles say it's a Chrysler-built rear, so I would guess it's the original one for your car.
Tapered axles and trunnion U'joint definitely say "Chrysler" to me. My guess, like R Pope's, is that you are looking at an original.