Front tires are 245/40/20 and the rears are 315/40/20. I've got room for more tire on the rear, but I'm happy with the 315 size and price. Since 315/40/20's come on several production vehicles, prices are much cheaper compared to a 325 or 335.

And a few pics of the wheels on the car...

1970 Barracuda B5 6.1 Hemi/6 speed
1969 Charger survivor in R6 383/727-wrecked 12/24/18
1968 Charger in original burgundy paint "Ribeye"
1968 Charger w/ 6.1L, TR-6060, 9"
1968 Charger...clean slate in epoxy
1968 Roadrunner w/ 6.1L/6 speed
2010 B5 Challenger SRT 6.1L/6 speed
2011 Dodge Ram w/ 6.7L