TRD 
2006 Toyota Tundra Access Cab SR5 4dr Access Cab 4WD SB (4.7L 8cyl 5A)
TRD
 Regardless of what some write ups may say, my suspension and drive train and much much more stiff than any of my friends other trucks.  I have the TRD and tow package and the suspension is uncomparable.  Even though the horsepower rating may be less,  It's "rear wheel" horsepower and not engine horsepower that's important.  Even with less horsepower, my truck will still beat all of the competitors in the 1/4 mile.  The drive train is very basic.  All of the power from the motor goes directly to the rear without any traction control and other HP robbing items.  The only problem is that I get a slight off start clunking from the rear.  But I'm finding out that this is normal for this truck.