Thought I would update with what I ended up doing.
I machined the new drums to match the old ones. I indicated the old drums on my granite surface plate and got the height at 3.535". I faced the new drums to match. I took off about 0.040". Then flipped it over and took off the remaining amount to make the face 0.125". I did this to insure the hub remained in the same place as original instead of just facing off 0.125".
