We used the 5/5/2 diff oils but the front tires were wearing out faster. Too much front tire wheel spin, so we changed it to 5/7/2. Front tire wear is alot better and it has better forward acceleration. We saw no change to on or off power steering with 7K center diff oil. Front diff oil will change that. Higher front, more on power/less off power is the general rule of thumb, but you have to try it and see. As you can see with the Kenji setup, he runs 7/5/2, which I hear most say they like and it really hasn't changed the off power steering. Get your car up and running first so you can baseline your cars performance. I know using the newer kit softer springs and swaybars calms the car down compared to the harder springs and swaybars.