backspacing and tire size on a minitub
 

i have a67 camaro with about a 3 1/2 to 4 inch minitub, i have a ten inch wheel with 7 1/2 backspacing, and the wheel is about one inch from the stock framerail. I need to get another wheel with less backspacing because it is too close to the rail, the next size is 6 1/2 inches so i think that will work. so that will be about two inches from the rail. my question is will i have enough room for the tire bulg at the top by the rail