Not true. The passenger side is indeed the different unit. Those images in Neil's original thread are mine (unfortunately so are the sketches and bad penmanship).
The knucklehead is the one who authored the Mopar Chassis manual section on modifying the bracket for doing the swap. It it plain to me that the engineer sent a lacky out to the garage floor with the instruction that he needed to get the dimensions off the "right side mount" and the goofball looked in the engine compartment, looked at his right hand, then took dimensions off the drivers' side mount. ](*,)
The difference between the 273 and 360 block is the configuration of the passenger side ears: the 360 only having one tab on the rear and two in the front, but the original 273 bracket is intended to use two holes in back and one in front. the rubber mounts are the same side to side (regardless of LA motor), but the brackets are indeed different on the passenger side for a 273 versus a 360.