Ground Cables/location(s)

Hey everyone, been a while since I posted last. As some of you know, I've been building a fox due to my last one (Blue 85 GT, carbed) being crippled from a deer. Well, I'm about done and need to install the ground cables. Something is weird though. On the 85 I had, the only ground cables were battery 2 the block, battery 2 the intake, & the weird one that goes from the block to the firewall. Now my understanding is the intake ground is for the sensors (water temp, oil press., etc.) & the one that goes to the firewall is for lighting the dash lights.

The current car that I'm working on is a 84 Mustang with a carbed 302. Convertible motor mounts. My questions are.

1.) Shouldn't there always be a ground to the frame rail?
2.) Benefits of putting one on the frame rail?
3.) Is there any benefit to running 1/0 gauge wires vs standard 4 gauge? That is 1/0 gauge wires for the + & - side of things. P.S. I am going to be running 1/0 gauge wires for the stereo system.

Thanks in advance. I tried searching. Everything that came up was for EFI cars and I am not sure if there is a difference between that and carbed, ground wise.

@Prime Lord Thanks for the help.

Audiophile said:

4 ga. is probably sufficient. However, if you have 1/0, you certainly aren't going to hurt anything by using it. Just be sure to stay away from any CCA wire.

How many watts do you plan on running on your system? Do you, or will you, have an upgraded alternator? These things definitely need to be taken into account when deciding what size wire to use.

There are some very useful charts and calculators on www.the12volt.com.

I always have a ground to the frame. Depending on the situation, I'll certainly grind off any rust, paint, or primer, and either use a ground block or a combination of a bolt, nut, and star washers.

Hope this helps. Best of luck.

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Thanks, that's what I was figuring. Stereo wise I'm using oxygen free wire. Around 3500 watts for the lows and around 600 for my highs. Working on the alternator currently, looking at a 300A-350A alt. I have a little audio background from working at an audio shop.

Will definitely be scraping the fresh paint off the frame rail.

Thanks again @Audiophile

Prime Lord said:

My suggestion on the alternator front.....don't play the "rebuilt" game. I went thought 5 of those damn things in about 3 months. And when the 5th one actually caught fire under the hood, I bought a new PA Performance one. It was 'spensive but I never had another issue.

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Ah, damn. I was hoping to just have mine upgraded, its currently the 140A. I have had a few experiences with fire, not something I would like to re-live. How big is your Alternator @Prime Lord?