It'll be more than redrilling drums, you'll be going from 8 lug to 5. I don't think that the hub on the ford axle shafts would be large enough to be redrilled to the 8 lug pattern. Finding wheels in the correct size might be interesting. You'll also be giving up some braking power, as the drums will be much smaller. Might come out ok if you swap the front axle to a 1/2 ton and do a disk brake swap so that the wheels and braking system can be matched.
