I agree with G35cas that with our V-6's, bottom end grunt is at a premium. To me the solution is either F/A or gearing such as the 6M/T or even steeper like a 3.7/1.
These engines are tuned to about the limit from the factory and that any mods like intakes and exhausts will only detract from low end torque in favour of more at higher rpms.
My $.02