4"x5 to 4.5"x5 drums

1968hemidart, I read the OP as about drilling out the brake drums to a 4.5"D bolt circle, 1/2"D bolts, not drilling the axles. I don't see any safety concerns with that. Drilling the axles does take more care, but I don't think there is a problem with "not enough metal".

I am considering the other way - drilling a 5x4.5" drum for 5x4" bolts since the rear drums are almost unavailable for 10" drums in early A's.