Hi guys, I'm breaking in a Magnum .70 4-Stroke and swinging a 13x6 right now. I eventually want to try a 3-blade. Is a 12x7about the size it should handle? I certainly don't want to tax this motor more than I need to but want that scale look without losing performance. I wont put this prop on until I've got my first gallon of fuel in it and flown. Can I expect a big difference in thrust and speed bychanging 2 to 3 blade? Will I need to revisit my needle settings? Thanks!