Mogul is techincally a size of socket, so what you have might not be rated for more that 175w. But assuming you have the standard procelin mogul sockets that are most common in our industry, you will be fine up to 400w. I am using a 250w bulb in the fixture I originally had a 175w bulb in. I would be careful if you decide to go to 1000w, but otherwise IMO you will be fine.