Besides a TransBrake

[quicksilverado]

They only work when they are engaged, so they work fine on the street. A 2-step is only used at the track. You stand on the brakes and hit a momentary switch. Then you floor the gas pedal. When the rpms hit the preset limit they will not go any higher. every other cylinder will fire and then they will alternate. When you release the brakes all cylinders will fire.

[GasGuzzler]

A two-step has no affect on street manners if you don't use it on the street. You arm and disarm as well as set it.