Bagged, how wide of tire question

[NEWFISHER]

I have standard bag set up, notch rear, plates front. No cups, no truss , no crossmember pancake or PB. 1st pic is on stock 73 wheels with 235/75/15s they measure 29" tall 9.25 wide. I am going to use some 8" slots with a 4" backspace and wondering how wide of a tire you guys can pull off stuffing into the stock wheel wells front and rear? Tires will be a raised white letter 60's look
255/70/15 = 29" tall and 10.04 wide
275/60/15 = 28" tall and 10.83 wide

Thanks for the help!