My experience is with a cousin - a '70 Challenger. I'll share and hopefully others with your combo will add. In general, a 225 tire in front should be an easy fit with ~7.4" tread width. In the rear, a 255 with ~8.9" tread width should be an easy fit. Bigger is close or can hit in more extreme situations of full lock and jounce/rebound.

I think your desired tire sizes are tight for a stock setup.

Also, I think clearance in the front would be better with less backspace... around 4.25" with 8" width wheel. Rear is OK with the higher backspace.

Before the big investment in wheels/tires any way you can get a test wheel/tire? A borrowed wheel and used tire even? This would help a lot. Mount and check fit. I did this to confirm before ordering with a really helpful tire shop.