265 will be very snug and if it works you will need a 5 1/2" backspace on that 8" wheel.. Lefty sent me some pics showing that the outside fender well curves in as it goes up creating the tightest area in the fender well..

On my 67 coronet I am going to use 245-60-15 on 8" wheels with a 5 1/4 backspace on the back.