I ran a 3.90 at Chilton and turned around 10,100 rpm. Chilton looks like it would fit inside Springfield which is why I am thinking 3.73. I remember asimilar coversation with people when wewent to big Diamond, some said 3.73, some said 3.90. I watched videos, looked at laptimes and went with a 3.58. Gear was perfect, my buddy went with a 3.73 and he had to change right away and lost practice time.
Not to be disrespectful to anyone but slower cars/drivers can get away with a higher gear ratio.
