"7.3" is somewhat of a legendary number in the realm of Ford trucks, normally related to the 7.3L Power Stroke diesel offered in the Ford F-Series from 1994 to 2003. But don't be confused - their new gas engine is in no way related to the previous oil burner manufactured by International-Navistar.
Little is known about the upcoming engine, although Ford is slowly letting details trickle down through the ranks. The engine will feature a cast iron engine block, forged steel crankshaft, high pressure port fuel injection, variable valve timing, and a variable displacement oil pump. Ford engineers seem to be in the midst of a balancing act, making the engine an economical alternative to the 6.7L Power Stroke while exceeding the performance (and likely capability) of the current 6.2L. Horsepower and torque figures have yet to been revealed but can be expected to exceed the 6.2L V-8, likely by a reasonable margin. The 7.3L will share a 10 speed automatic transmission with the 6.7L and 6.2L engines, although it differs from the current 10R80 found in the F-150 and is being marketed as a member of the TorqShift family.
Fuel economy is unlikely to be reported unless the engine somehow finds its way into an F-150 model; fuel economy ratings are not required by the EPA for 3/4 and larger pickups. More details to come as information is released and confirmed.

Source - Ford Motor Company
Ford 7.3L V-8 Specs
Engine: |
Ford 7.3L gas V-8 |
Configuration: |
V-8 |
Applications: |
2020 Ford Super Duty |
Assembly Site: |
TBD |
Displacement: |
444.88 CID, 7.3 liters |
Bore Diameter: |
4.220 in (107.2 mm) |
Stroke Length: |
3.976 in (101.0 mm) |
Compression Ratio: |
TBD |
Firing Order: |
TBD |
Engine Block Material: |
Cast iron |
Cylinder Head Material: |
Aluminum (to be officially confirmed) |
Fuel Type: |
Unleaded gasoline |
Fuel System: |
High pressure multi-port fuel injection |
Aspiration: |
Naturally aspirated |
Ignition: |
Coil near plug, dedicated ignition coil for each cylinder |
Engine Oil Capacity: |
TDB |
Peak Horsepower: |
TBD - estimated > 400 HP |
Peak Torque: |
TBD - estimated > 450 lb-ft |
Coupled Transmission: |
Ford TorqShift 10 speed automatic |