I have 4.10 in my auto '03 V8. You can't beat them for super torque. I'd say that they would be great for a V6.
Gas will suffer somewhat. At least, it has for me. Then again, you are driving a V6 as opposed to my V8, so I'm not sure if it would effect you as much or not.
If you are really worried about gas, I would go 3.73. But if you really want some torque, go 4.10.
Sometimes I wish I would've thrown 4.30 in my auto.
