The Fairlane already has provisions for engine mid-mounts but they’ll have to be modified to adapt to a motor mount that attaches to a Y engine. Using 352/390 FE mounts for a ‘63/’64 Galaxy are more compact in design and will bolt directly to the Y engine. These will possibly allow the Y engine to sit lower in the Fairlane chassis without as much frame mount attachment fabrication on the body. Without looking at the Fairlane engine compartment, I’m thinking you’ll need a front sump oil pan on the Y engine to clear the steering.