[Dave at Pelican Parts]

I know that you need to "spot-face" the back side of the hub when you re-drill for five-bolt. Are there flat spots around the existing four-bolt holes? If not, then you need to take the hubs off and put them on a mill.

You will have to remove the fronts, but happily that's not too awful. I am less certain about the rears, but I'm thinking there's a good chance you will. You can always pull off the rotor and check...

--DD