by going straight to the battery your helping flow that much more...your amp is hooked directly to your battery right? Just like why wouldn't you hook your amp up to the fuse block? Because voltage flow isn't as good there...go straight to the battery, heres how..use one of these available at napa...
http://www.darvex.com/miva/merchant....Code =SGMBATT
just go to napa and tell them you need a gm battery terminal with the extra screw in the end...
2000 ECSB, 5.3, magna flow cat back, some beat in the back and a killer front stage