Chevelle SS tire size

I am a new owner of a 1969 Chevelle SS396. I have new 15x8 SS wheels and need to buy tires. I'd like to go with bigger tires on the rear than on the front. Anybody recommend what tire sizes I should go with?

I have 235/60/R15's on the front and 245/60/R15's on the back. BF Goodrich Radial T/A's. Darn good tires for the money. This is on my '68 Chevelle.
Although I have 15 x 7's on the front and 15 x 8's on the back. This combination makes a good looking appearance - not too big or wide, not skinny like stock. Handles nice too.