Hi there, i bought a 2003 discovery 2 with what should be a 4.6 litre engine. But it doesnt have the power. The stamp on the block is 94D11589A. I took it to a mechanic and we opened the bottom of the motor, to find out the crank had 4.0 stamped on to it. Does this mean i got screwed? If it was actually a 4.6 it should have had 4.6 stamped on the crank correct?