Motor mount questions

Dave, use both of your 318 motor mounts on your 340. That's assuming they are the sandwich type that were originally on your car. The right side will fit with no modifications. When the left side mount is installed, there will be a space of about 3/8" between the rear of the 318 mount and the 340 block mounting ears. Just slip a couple of washers in to fill this space, then run your mounting bolt through the motor mount, the washers, and the block mount. I had a picture of this in one of the threads here, but I'll be damned if I can find it now.