Head spinning! Seeking advice for tire/wheel fit, '66 Barracuda.

Hi, I've combed through all the posts via the search function. I have a '66 Barracuda and I've decided to upgrade to Vintique 15" steel rims. What is the largest width/backspace that I can fit with original leaf springs, fenders, and ride height? Any recommendations for a setup?

Any photo galleries out there with photos/video that I can check out?

Thanks in advance!