Time to order wheels and tires.

What's really going to suck for the OP is having to cut fender well lips for an extra 1/2" of clearance... And these old A-Bodies look way better with mini tubs and the widest tires that work with that. So why would you have the car about done with a rotisserie paint job and assembly and not have rims & tires picked out yet?

I would have started suspension and tires way before I decided to rotisserie paint the car?

He doesn't have to cut anything to run the tires he wants to run (245's) if he sets the backspace correctly. Mini-tubs are fine, but unless you're going to put down more than 500 hp its all just for looks and a waste of money anyway. You can run 275's on a Dart with a 1/2" spring offset kit that will bolt in with exception of moving the spring perches, no need to repaint anything. Those will handle plenty of ponies. If you want to run 335's then yeah you need mini-tubs, but honestly for what most people actually do with these cars it's a waste of time, money, and more money every time you buy a set of tires.