Can anyone with a Wilwood kit explain this

I am sorry. I think I miss understood the first question. I checked the Wildwood site and was surprised to see they have the rotor hubs in both 5x4 and 5x4.5..... but both with 1/2 studs... that does not make this a bolt in deal at all. Not only does this cause a problem with stock wheels fitting and or getting a good seat on the lug nut flair you also have the issue of doing something with the rear axles.
I sent a question to Wilwoods so I am eager to see what they say.
On a side note if I can get a set of Wilwoods in 5x4 to work on my 68 formula s I will become their biggest fan!!!:prayer:

Although my measurements say they should fit the SBP wheels, this is still a concern of mine. Wheels may differ, and whether or not a 1/2" lug nut will seat properly in a hole meant for 7/16" studs is the remaining question, regardless.

The holes in my stock steel wheels were about .552 inches in diameter.