If you run the battery to ground you have to have an equal ground cable from frame to block. My BMW has the battery in the back corner of the trunk grounded to the body and with a ground cable from engine to body at the front. My Cad DTS had the battery under the back seat as did my Audi 5000 never an issue with any of them ground wise. I'd agree on wimpy cables being an issue though. Had that on the 454 in my 1 ton. Those regular off the rack 4 gauge cables wouldn't handle the load but the 1 gauge work great. I have to agree with Steve, 1 gage cables and good clean contacts for all connections. You have to clean the contact area to bare shiny metal as that paint is a good insulator.
I also agree with Steve, on cl*** 8 trucks, many use 4 group 31 batteries mounted a good distance from the starter. On a cold day, a 15 liter diesel might draw 750-1000 amps on a starter draw. These trucks ground from the batteries to the frame, AND then from the frame, next to the starter, to the starter itself. Apparently Freightliner, International, etc feel the frame is a good ground as long as you also have a cable from the frame to the starter.
The Jalopy Journal
