The battery grounds to the engine block and the engine grounds to the body. A ground cable to the firewall is usual from the head of the engine. You CANNOT have too many grounds from the engine to the body! If in doubt add another one or two.
Make sure the cable surface and the engine or body surface is sanded clean so the grounding can be effective.
Lectricity don't like to pass thru rust, paint or other corruption.
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

professional bovine relocation specialist