Do I need a specific type of 4 gauge wire for my monoblock amp?

The 40 amp fuses are located on the outside of the amp. (Idk which conductors. I took the safe route, and ordered another wiring kit. Its an OFC (copper) 4 gauge kit. The one I ordered last week, that hasn't arrived yet, was a 4 guage CCA (alluminum) kit. Hence why I was worried about wiring such a powerful amp through alluminum.

I have one final question. The amp is missing ONE set screw. Its an M7 set screw for the power or ground on the amp. Ive looked everywhere. So my question is, how can I securely connect the power (or ground) without that set screw? Can I solder something to fit the end of the wire??

120 amp fuse  that  is higher then the current going through any 
wire in you home. Most houses have a 200 amp service for the whole house. Is this amp for a Stadium ?  I have never seen in 
Audio ever a 150 amp fuse 
 

To handle a 150 amp load youwill need a awg-1 gauge 
in a copper wire ,justlook up the awg wire index for 
150 amps and wire size requirement . Something does not sound right ,this is not for a home ,  even on big power amps 
they use only a 20 amp circuit .i owneda Audio store In the UK
and into Audio over 30 years . Something is not right ,
thereos no home amplifier higher then a 15  maybe 20 amp fuse .
you need to tell us what model brand  and age 
call JBL . If this isaindustrial Amplifier for a outdoor concert 
that is a whole different ball game.

This is for a class D monoblock subwoofer amplifier. Crutchfield said I should use one that's at least 120 amp.

The fuse goes between the battery and the amp itself.

Class d amps have a higher output than most other class a or a/b amps.