With the early A Barracuda, there is not much room in the fender well - I will have to do some measuring, but I am pretty sure that with an 8" wheel it will be not quite enough backspace and will have clearance issues.
JMHO, but I believe you are correct - 8" wheels will not fit. I have a 66 Valiant with 15x7 steelies with 245/60/15 on the rear, and 15x6 steelies with 215/65/15 on the front, and it's all I can get in there on both ends. There is just enough clearance to work, but there's nothing more to work with.
