Even on the under-powered V6, your 1999 to 2004 Mustang's drivetrain is absolutely critical when it comes to getting better performance. Updating your Mustang's rear end gears or swapping out your factory shifter with a short throw shifter can change the entire feel of your six-shooter Mustang with acceleration off the line, through the curves and shifting. Make sure to also check out our 1999-2004 Mustang suspension upgrades to keep it all under control.