The disconnect needs to interrupt ALL the current flow, as it's the only way to positively prevent parasitic drains on the battery from infrequent driving and/or short circuits. Run the ground cable TO THE BLOCK first. The more connections you add between the battery and the starter, the more possibility there is to have a high resistance connection or a loose one. Making two extra ground connections for the starter current to go through serves no useful purpose. "This ain't rocket surgery!" The simplest circuit is usually the best, and millions of stovebolts managed to have a long useful life without fancy stuff like a battery disconnect. Since it's already there, go ahead and use it, but it's really an unneeded extra.
10 gauge? Maybe you mean 1-0? 10 gauge primary wiring is used in places like the charging leads from the generator to the regulator, the ammeter, and finally to the battery cable terminal at the starter for battery charging. It's definitely not meant to carry starter current.
Jerry
