4th gen brake rotor help

[mhotel1]

I am putting 4th gen rotors and calipers on a 69 Camaro with drum spindles. everything seems to line up fine with the bracket i have after turning the hubs down but i have 1 concern: The bolt holes in the newer rotors are much larger than the stock 7/16 wheel std size and the rotor seems to be to lose on the hub. The holes in the rotor are even bigger than 4th gen studs(12mm ~.480)...My question is will this be to lose? do i need to drill out for bigger studs? it just looks screwy