To me it just feels like its great from 0 to about 80. Then all the power slowly fades as I get higher and higher in speed. But I hear stock 2. 73 sucks in acceleration but once it gets going it really moves. I even herd in a long distance race or a race from a roll the 2.73s come out on top.
I'm wondering if it's your tune because if I'm in 6th may car starts to really take off at 80 and doesn't really start to slow it's acceleration until around 120 but keeps climbing past 140.