Well, its actually a 9.75 inch rear Goop And the stock suspension does do pretty decent with drag radials. If you want to get really crazy with it then you have to start messing with the suspension to hook. Lots of guys easily into low to mid 12's with bolt ons on the stock suspension with good tires (drag radials or slicks). Also, its 450 tq, not 390 - they make a gob of torque very quickly.