1970 cuda max. tire width size

I'm considering buying new wheels and tires for my cuda. I now have 14" factory magnums with 235/60 14 tires. I would like to go to 15", as the 14" seem to not fit the wheel well correctly. I'm looking at classic Cragar S/S rims. I would like the maximum size front and rear if anyone knows. Thanks
Author: cudanut jim