Both those front and rear tires are going to be useless for the track, so you're in for a set of new rubbers all around. If the rears are 15x10s you will need to do a fair amount of work to get them to clear the OEM brakes. If they're 15x8 which they probably are, they will still require grinding, but not as much. I've never seen anyone fit a wheel over 4.5" wide on the front of a LS1 car in a 15" diameter, so I don't know what size fronts he is using with those tires.
2014 Shelby GT500 - 2002 Camaro SS - 1972 Camaro SS - 1969 Plymouth Barracuda - 1967 Camaro