Im assuming the amp has screw terminals for 1/0ga wire and the fuse block should also ave screw down terminals. and the wire itself should be wired to its own terminal at the battery - the terminals usually crimp the uninsulated wire with bolts.

If you have other aplications then I couldnt imagine but keep in mind that a 3ft segment of 4ga wire can handle 200 amps without any real resistance so alt to battery and gnd to chasis dont need to be any bigger than 4ga unless you are pushing 1500wRMS+


orchard supplies is in california but they do mail orders. I dont have the link as I havent used them in years but im sure you can google it.