try checking to make sure the contacts on your current ground wires are clean.

If you want to make a kit, use 4 or 8 guage wire, and make sure you solder the connectors using a butane/propane torch. I'd suggest using 8-guage since it's easier to work with...

Don't count on this to make any noticeable improvements of any kind, unless you're replacing bad wires, which you may have.