would it be ok to run the chassis of my alternator (aka alternator (-)) directly to the negative battery post? is it ok to have long wires in the big 3. i am using 0 gauge and want to have the capacity to run 3kw rms. should i run two runs of 0 gauge since i have wires over 5 feet long?
One run of 0 gauge is more then enough for an alternator.
And you can connect that ground wire from the - battery to anywhere on the engine. Doesn't have to be the alternator chassis and it makes no difference.
As long as you do engine to - and frame to - and alternator to + with 0 gauge you're good.
would it be good to sand the mount and the alternator chassis where it meets the mounts to get better electrical connection? obviously i know to sand at the grounding points and the battery terminals.