That sure is a new one.

Swapping gear ratio and changing it in the PCM will really do nothing but reduce gas mileage and make it a better drag car.

These car will see a good amount of load in 4th gear but its not harming the car, we can see upwards of 35-40+* timing while crusing to get the good mpgs. Once the car is moving its not really working at all to stay at that speed.

Adding a set of headers is the one of the best things to do to reduce KR when going WOT and during modding.