what the spider does is make you oil thicker with more surface are, more teeth (7k is more like 10k and 10k more like 15k and so on). if you use 10k in the center, throw 10k in the front. this will turn your inside tire faster and pull the truck in at turns, also use a little more rear brake bias. i have my brakes set at about 30% rear drag at neutral, no front, and then 50% front 100% rear at full brake. my truggy had major push problem till i went with 10/10/3 on the diffs, give it a shot. i like to throw the back end around in tight corners.