big 3 upgrade questions

[GMCJimmyslt2000 10+ year member]

the bigger the better but 1/0 isnt ness. until 2000 or around there.

 

[quins90lac 10+ year member]

ok i know i all ready got a fail for tying to answer a question but o well live and learn .Any way is there a certain size fuse i should use when doing a big 3 upgrade with 4 gauge and if latter on i up grade to 0 gauge do i have to go up in fuse size? Other thing im wondering is can i run a circuit breaker in place of a fuse or do i have to use a fuse