Where is the best place to ground battery. Right now mine is grounded on alternater bracket. When idleing it is fine, but when driving the volts drop up and down and it messes with all my gauges. Also moves around when blinkers on.

 

Generally the negative battery cable is grounded to the engine block or the alternator bracket... Depending on engine, year, etc. There's usually a smaller gauge pig tail that grounds to the inner fender next to the battery. However there are grounds scattered all over the car. Usually there's a braided ground on the back of the drivers side head to the firewall, and the engine harness usually has a few grounds to either the back of the passengers side head or the intake (sometimes both). Then of course there are a few different grounds under the dash, under the seats, and throughout the interior.

Your best bet is using a GM Service Manual to troubleshoot individual circuit problems.

 

This is an 85 camaro with a swapped in 68 327. I would like to maybe estabish a better ground with baterry and then work from there. Where on block? Just anywhere there is an extra hole?

 

Front of the cylinder head is where they grounded most of the later cars... Pretty much any clean open bolt on the block is going to work just as well. Make sure the ground from the engine to the firewall is there and tight.

 

Sweet. Thank you. I appreciate it