MEL is the Ford acronym for Mercury, Edsel, Lincoln. FE is Ford Edsel.
The FE is a Y block in that the crank hangs lower in the block than you're used to seeing on more modern engines like the M engines. The block is basically a Y configuration looking from the front or back. Bolt patterns are specific to the MEL and FE.
A fuel injected 302 is going to be no better at gas mileage then the engine it came with. Lincolns from that era are huge, heavy cars, many well in excess of 4,000 pounds with really bad drag co-efficients.The 5.0 with 300 ft lbs of torque is going to struggle to pull the car and the faster you go the worse it gets. That's why they put huge engines with gobs of torque in them.
No, a 302 is not a FE, it is a Windsor.