Wheel Size for 1968 Barracuda

235/60/15's in the front will be difficult with the wheel openings on a Barracuda. That tire is 26.1" tall, and the lower front corner of the wheel opening is pretty darn tight on a Barracuda.

Take a look at this post about the modifications needed for a 26" tall tire on a Barracuda. This particular modification was to run a tall and wide tire, but the height is a larger factor. The 235/60/15's might not require this much, but it will depend on the backspace as well. Definitely something you need to consider at least

1968 Barracuda Front Fender Modification for 26" Tires