I did hear about that motor. Near as I can figure it is a modified 4.6. Perhaps they used the standard 5.4 crankshaft to gain the extra cubes?
Now the 5.4 there using in the new GT-40 should NOT be confused with the existing 5.4 they use in the BIG Fords, SUV's and trucks, etc.
The "new" 5.4 just happens to share the same bore and stroke but it is a TOTALLY new design. For instance it was desgined from day one to be a "dry sump" motor. It CANNOT accept an "
oil pan" without modifications to the block and the oiling system! It was also designed from day one to be a super charged engine. Extra webbing in the casting of the block, a lower end "girdle", "trick" H-beam connecting rods with a VERY unusual wrist pin design. The wrist pin may be a first for a gasoline engine but the idea came from DIESEL engine technology!
The new 5.4 is indeed an awesome design. Count on it eventually finding it's way into some of the other Ford product lines. Like maybe a potent Lincoln or full size car? Probably NOT a SUV or truck application I would think.
Ernie