Max tire size - 68 dart

Hey guys, I'm getting ready to buy some police wheels and tires for my new 68 :)
I want to make sure they fit.. I'm new to the boards, is there a thread that talks about max tire size for different models?
I'm thinking a 225/60/15 will fit in the front, but would like to go bigger in the back and don't know what choice I have without doing a leafspring relocation.


Thanks for any help!