Rear Disc brake coversion "Fiasco"

[Fldawg]

So i started my rear brake disc conversion today on my 70 which should have been done before i had it painted, so instead of pulling the axles like i should have. I thought i would cut the backing plates off only could go so far with the cutting wheel i had , so had to pull axles anyway that was the first snafu. got everything cleaned up and went to slip my new rotors on and the hole in the middle of the rotor was too small, well that was just a OH **** MOUMENT!!!!
so now i need to see if i can get my rotor center machined out and i hav'nt even put the brackets on to see what kind of centering probelm i'm gonna have.
Long story short has anybody else had this probelm before. I'm sure i'll figure it out, but nothing on this truck has been a bolt on like they say.

Oh by the way i'm using 88-91 k-1500 rotors and metric gm calipers with some brackets i got off of ebay. i will post more of this adventure tomorrow if weather permits..