How did you LBP your rear end? On my 69, I used c-body 11x2 drums and B-body length axles. This pushed my rear track out wider. You may, depending on how you set the rear up need a more positive offset. On my car to center a 15x8 wheel I need a 5.5" backspace.
In MilehighDart's case, he used A body length axles and kept the stock rear brakes keeping rear length the same, so what fits his car will but the tire into or too close to the quarter panel on my car. And I so with I could run those Rev 100's....
This is all if you used an a body 8-3/4 housing.