The jet in the picture is definitely a Block 40. In addition to the exhaust, you can also tell it's a wide mouth by the placement of the EPU indicator due to the difference in shape of the inlet. On a 40 it's on the side of the intake below the right intake light, on a 42 it's more at an angle on top of the intake above the intake light. Not too sure about the tail number and whether or not it was photo shopped, but the jet in the picture is definitely a 40.