Man I will half to say those are pretty good 1/8 mile times for no more mods than you have on your truck as of right know, but yes I do agree your 1/4 mile times are a lil bet off. In case the 4.8 just don't pull hard on top end. I know before my supercharger my truck would shift out at 6200 from 1to 2nd, and thats when i ran my best times. When I backed it down 58-5900 my times drop about .10 in the 1/8.