Personally i would NOT recommend a 30% COG with that hull. The hull will run very wet and you would not be pleased,especially if you don't run in salt water. From my experience running and building many GTX hulls and knowing what COG changes Mike had to do to his 70" Outerlimits with single mod Gizmo 29cc motor in order for it not to run so wet i would recommend between 25% - 26" COG and nothing more.