Another thing to factor in is that in racing, you are making your truck as light as possible... that takes stress off alot of parts, but it pulling you are adding weight(generally, to include the sled) and this adds stress to each part. And in pulling, since the weight goes up the farther you pull it, the more stress is added with each foot. Most breaks I see in racing are in the first 1/8 mile in pulling most breaks you see are over half track. Just my $.02