@ Jag, It is always a trade off. A good rear can be overpowered by too much front bite. If you have traction roll problems you'll need to get more rear or less front. Using 40's might be all you need to do as it just takes a slight amount of initial bite away from the front.
Anyhow more rear grip will always mean less steering in a way. Try the front diff and sway bar adjustments they are easy to make while running and you immediately feel the change and see if you like it.

@cyclops, normally lighter rear oil will not give more forward on power traction in the rear. More often stiffer damping will give better results.