I have changed rearend gears from 4.11 to 3.08, I have a 3 Speed w/ OD, 15" wheels with 27.5" tires. I also have a GM aluminim intake & Q-jet carb that I am trying to find best combo of primary metering rods & jets for, lots of info on maximizing performance,1/4 mile times,but this is no racer.