I don't know if there is a mechanical problem or if this is a normal situation but did you have a look at the curve of the torque vs the rpm? After an initial increase, the curve slightly decreases at medium rpm and then increases again at high rpm.
Captain Bart
1999 Black/Midnight Blue SVT #1949/2760
Built on 04/20/1999
Received on 05/07/1999
Sold on 08/03/2006