No reason to run a spring AND fuel tubing. When the spring is very close to being compressed it is already very stiff and acting like fuel tubing; adding tubing in there just takes up adjustment room.
Todd - Casper's post was dead-on. Adding washers will smooth out steering and help keep the front end flatter (less camber change). Removing washers will give you more aggressive steering and the front end will feel softer (the tire will also have more camber change). There really isn't much effect with respect to being on- or off-power.
Positive camber in the rear has the same effect of making the camber link longer; it keeps the rear end flatter when cornering, which puts more pressure on the tire and creates more sidebite. The inside (inweighted) tire now has more rubber on the ground and can offer more traction.
SoFast-NT - The new truck is really good. Everything sits very low.
D Mac - 45 minutes should be no problem.
Lane - Shane and Troy suckered me into doing this..haha. I'm not sure if we're going to Titus; we have the Gas Regionals left still this year.
Brian - In addition to the extra anti-squat, here's a few other things to try:
Move your rear hubs forward. Run the outside hole on the front bulkhead with no washers to give your car the most steering. (You may also want to dial in 1/2 or 1 degree of toe-out to make the truck even more aggressive).
When I want my cars to be aggressive, I want the rear end to follow the front end instead of sliding around the corner. Positive rear camber won't really make the truck want to swing around corners but you should be able to rail around them quickly. Try short rear arms if you want less overall side-bite.