69 vert camaro - rear upgrades

[69z11]

I have a 69 vert camaro, putting in 496bb, 650hp, 560 torque, 6 spd, ford 9", subframe connectors, hotchkiss handlebars, tubular upper/lower control arms, front/rear sway bars, caltracs. None of this is in yet. All stock subframe, body panels, wheel wells, multi leaf set up. Want wider tires than 275 max capability now. Wanted to avoid cutting original metal. Can a new multi link rear subframe be bolted in to replace factory subframe? Will the inner wheel wells have to be cut out in order to replace with mini tubs to handle possible 295 to 305 width tires. Don't want to flare out fenders. Want to retain original body lines.