if its amps -the engine/tranny need 1 big ground to batt, 1 big ground from engine to body, you should have 2 smaller grounds from batt(ground) to body, I also like to run 1 more big ground from tranny (ground point for 1st big ground wire) to alt bracket/arm, the body ground wire I said run from this point; I like to run to fuel filter mount.
the 2 smaller wires from batt(ground) to body are important
I also like to run 1 more ground from batt (2 smaller wires, same size as 2 wire ground to body) to a different body location.
make sure all metal on body is clean, bare metal(you can also after this, seal the points.). make sure nuts/washers are clean/or new. use plenty of washers! for more contact area(like at least 1 per contact point.).
check voltage drop, I think its burn money has a link for checking for voltage drop, its on this web site anyways.