where to attach main amp wire under hood

Hello all. Got a question for the pros. I am going an install on my 04 Trailblazer. Right now I am running 4 gauge from the battery (there is a 150a fuse in line under the hood) back to a fuse box under the back seat, which will then split to two 8 gauge wires, one leading to a JL Audio 300/2, the other to a JL Audio 500/1. The battery is a side post. The positive terminal has several wires coming off of it; one of which leads about 6” away to a 125a fuse, when then leads (I think) to the rear fuse block (under the back seat). My question is this: is it ok if I add another O ring connector to the battery side of this fuse and attach my 4 gauge wire? Or should I tie directly into the battery? The positive terminal on the battery has a large plastic piece around it, so I would have to remove it, cut up an O ring, place is between the battery and the terminal and then tighten it back up. Obviously, it would be easier (and I think “cleaner”) to tie into the wire already coming off, but what do you think? I (hopefully) have attached a picture to help illustrate what I’m talking about. Thanks for any input.

Technicly you can do that but there is a reason why there is a wire that thich running from the battery to the fuse and you are going to be drawing far more power through that short 4 inch piece of wire than what the manufacture ever intended. What I would do if I was you would be to get a side mount extension post which basiclly replaces the grey fatory one that goes through the large red boot. After you tighten it up there is another bolt that crews to the inside of that bolt, and thats where you connect your amp wire. They are very clean and essencially fool proof.double-secret reverse-osmosis speaker-cone-induced high-level interference distortion, Its a killer

that sounds like the way to go. where would i obtain something like that? car audio store, wal mart, autozone? thanks.

I am not sure if wallmart sells them and I dont have auto zones up here but car audio stores will almost surely have them. I would die without those damn things in my shop.double-secret reverse-osmosis speaker-cone-induced high-level interference distortion, Its a killer

Here or here or here or here. There are probably more, but I dont feel like looking for any more. This took about 90 seconds to find these four though...It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

the second link, the pheniox gold style ones, are the ones I usually use but I also make sure to use lock tight o the inside bolt after I had one customer come back where the bolt had backed itself right out after a couple of days and fell right off. I was baffled as I have never had it happen before but whatever, I guess shi happensdouble-secret reverse-osmosis speaker-cone-induced high-level interference distortion, Its a killer

Autozone sells them, if you have one of them you won't have to pay shipping