Fender Lip?

I have 255/50-17 tires on the back of my 72 Challenger with 8" wheels. When I have someone sitting in the back and go over a bump the driver fender hits the tire. The fender has quite a lip on it so wondering if using a wood block and hammer is the best way to bend that lip up little to give more clearance? I can put my fingers in between the tire and top of the fender at an angle but not straight up and down