I've has 10.5 for several years with different SB combos and they work well. As stated this car is tubbed and needs new tires. A 12" would fit easily. I'd like to take advantage of the larger size tire and see what it would do. I've got some HD wagon shocks that are extra long. So with all this info that has been discussed, a bigger tire is only a small part of the hook or is it a extra layer of stick on a marginal track condition or more?