I have found that when running the largest props recommended by the manufacture, you cannot run them with the same plug and fuel as with a smaller prop. To lug the largest prop around you will need to use a cooler plug, or lower nitro fuel, or both.  However you will be well below the power band of thie engine.  I would suggest the best solution is to use a smaller prop.  Since you want to hover I would chose a lower pitch over smaller diameter.