I'd want the gasket bore dia no more than a hair larger than the cyl bore dia so no excessive crevice volume mixture that doesn't get burned. not sure if the fire ring can overhang safely at all & if not & if you got the smaller one & if was off a bit you may or may not be able enlarge slightly the bolt holes to where you can shift it in one direction to where all cyls are dead on. if the gasket holes are dead on as is then I definitely would want the smaller gasket bore gasket but a person would have to make the purchase (1 of em at least) to find out. Cometic is good but pricey & for that kind of money I would expect em to be dead on! Do ya feel lucky? well do ya. Holler how it turns out