I'm in hell, how can this be possible for a stock gear???

[96_4.6]

Took my 96 gt in today for 3:73 gears, the gears have never been touched the car was stock when i bought it last year and the guy calls me and says theres already 3:27 gears in here if you wanna feel anything go 4:10 plus he said they had to rebuild the posi unit and put in new bearings so from $450 I have to pay $700 cause i'm too much of a pussweed to say no so now i'm gonna have mega crappy gas milage and less traction. With the "3:27" in there already i still really could spin the tires and i'm never gonan supercharge it and i dont drive freeway so with 4:10 i lose alot on the high end like if i'm crusin 55 and a camaro pulls up and we both punch it i wont have much left right? damn it damn it damn it