I'm thinking the easiest way to power my stereo system is to run the power and ground directly from the battery. Is there any reason I can't use the top posts for the power to the stereo and the side posts as the main power to the vette?

 

Nope, just make sure to fuse it, and it's wise to use a switched 12V source for the head unit so the radio shuts off with the car. You'll eventually forget and kill the battery otherwise.

 

Thanks, I'm only planning to power the subwoofer and speaker amps from the battery, I'll power the head unti from the existing radio wiring harness.

 

Internally the posts are connected together.
I ran my stereo off the top posts for a long time, no issues.
One word of warning though, if you run a battery disconnect and forget to connect it, or have a poor main ground (or power for that matter) it will try to pull through you stereo instead. Proper fusing is even more important than normal.
Also watch where your head unit and amp(s) ground so you don't end up with a loop.

 

is not ground common thru the entire car ?? so will be a loop no matter where grounded

 

As mentioned, you're fine using the top posts for your stereo. You can also get top post adapters to replace your side post bolts, effectively giving you both that way. Not sure if you got the dual post battery yet, but Advance Auto parts is running code "ES123" $30 off $100 if ordered online. Not sure for how long, but worked Thurs 12-22. I have their Gold 34/78 dual terminal, and 3yr free/7yr pro rated.

 

In a way it's always a loop but the higher end equipment is fussy about "clean" power and if it can get different "routes" to that you end up with various different potentials which is an electrical no-no.

(Louder exhaust will usually cure the problem)

What happens, in multi unit systems (head unit, amps, disc changers etc) is since they are all connected to each other (usually the RCA cables) and contact the car in different way(brackets etc) if one of the units (for some reason usually seems to be the head unit chassis ground) will be grounded to the chassis (dash bracket, etc) while something else is grounded directly to the battery or to a real good ground (frame or bracket near an actual ground strap). Electricity being what it is, tries the route of least resistance and starts using the inter-connecting wires to get to a good ground instead of the one you tried to give it.

You can sometimes see this when you disconnect the negative wire for the radio or amp and it still comes on (sometimes just faintly) as it finds a ground through the antenna wire or some other path.

By hooking all grounds to a common point, all units get the same potential and the unwanted flow between the units should be eliminated.

There are ground isolators out there but it's like fixing an electrical problem by putting a bigger fuse in.

Tons of info on ground loops available on the net (some people are rather obsessive about it so be careful)

Again, not an expert. Actual mileage may vary. Belly buttons.