I suggest you check on yellowbullet.com and look at the wire sizing chart:
http://www.yellowbullet.com/forum/sh...ad.php?t=47266
it looks llike 4 gauge would be better. I use 1 gauge for the 3' to my RobbMc mini starter from the junction block because too big won't hurt, and the junction is 24' from the battery (2/0 to the junction from the battery). Also, the initial surge needed may be a lot more than the running amps.