Redrilling Brake drums for 4.5" bolt pattern

my drum are drilled now //didnt weld anything up on them just turned the drum to it had new metal and drilled . not a problem yet=D> been that way for some time now..had a set off stock axles drilled also no problem there either...and they have been 6.20 in the 1/8 mile i think 1.3x 60' with wheels in the air