Using 273 mounts on 340 66 Dart
On the passenger side, the 273 block and original bracket had one bolt in front, two in the rear. The 340 block will have two bolts front, one rear. Solution is to weld a triangle shaped piece to the front ear of the original 273 bracket, and drill a hole for the second bolt. Here's a picture I took a couple of minutes ago of the one on my 65 Barracuda. (A little blurry, but I was lying on my back and pointing into the dark.)
Note: for several years after Chrysler changed the small block motor mount bracket design in 67, the company continued to offer two separate passenger side brackets. Eventually, they started making a bracket with two holes front and two rear, so that one bracket would work on both 273/318 and 340/360. Can't remember what year that was.
Anyway, below is what a 64-66 A body 273 bracket looks like when modified.
On the passenger side, the 273 block and original bracket had one bolt in front, two in the rear. The 340 block will have two bolts front, one rear. Solution is to weld a triangle shaped piece to the front ear of the original 273 bracket, and drill a hole for the second bolt. Here's a picture I took a couple of minutes ago of the one on my 65 Barracuda. (A little blurry, but I was lying on my back and pointing into the dark.)
Note: for several years after Chrysler changed the small block motor mount bracket design in 67, the company continued to offer two separate passenger side brackets. Eventually, they started making a bracket with two holes front and two rear, so that one bracket would work on both 273/318 and 340/360. Can't remember what year that was.
Anyway, below is what a 64-66 A body 273 bracket looks like when modified.