Motor Mount modifications for 340/360 into Early A

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.
I modified both of mine when I swapped my 273 for a 360 Mag into my 65 Dart. The lugs on the driver side of the 360 were the same configuration, but were wider apart. The front lugs are in the same location, so I cut off the back ear from the mount. I bolted the mount to the front lug and then bolted the rear ear to the lug and welded it back to the mount. The passenger side (360) has the lug with two holes in the front and the 273 has that lug in the rear. they are the same spacing as the 273. I simply added a piece on the front of the mount to line up with the other hole on the front lug. It has an extra hole in the back but it doesn't matter.
easyrider