I'm a big stickler for grounds. I personally have 2 gauge wires on my battery.

1) gold plated brass battery post terminal with a 2 gauge cable going to a 4 fuse Distribution block with 3 inputs, one of which ..[sic]

Dave,

What brand is the Distribution Block that you are using?? Where did you purchase it??

Thanks,

By the way, Aluminum is Crappy for grounds or any kind of power transfer. Use Copper, tin, brass or gold plated brass or copper.

Dave

Now that you mention it, I don't remember if the ground bar I used was aluminum, or tin plated copper. Either way it will have a lot less resistance than the bolts that you use to attach it to the firewall.

Actually, aluminum is a much better conductor than iron, nickel, or lead, and nearly the same as gold.

http://en.wikipedia.org/wiki/Resistivity

The bad part about using aluminum in high current applications is that it has a high coefficient of expansion. This causes it to work non-locking screws loose and leads to arcing problems over time. That isn't a condition you are likely to ever encounter on a ground bar.

Still, I wouldn't recommend using aluminum wire for the ground wires themselves because it is too brittle.