SSBC rotor rubs on bolts for steering knuckle

I bought a W153 front disc brake conversion kit from SSBC. I was putting it together and found the bolts that hold the steering knuckle to the adapter plate and spindle rub on the rotor. I talked to their tech support and they told me that the bolts have to go in from the outside. I don't think this is possible because their threaded plate mounts on the outside and the bolts aren't threaded to the top. As soon at the bolt stops being threaded, the bolt will not longer go in. Even if this wasn't the case, the bolt head is the same size as the nut (3/4) so it would still rub. I told them this and they have not gotten back to me (been about 3 weeks).



It seems to me like the rotors are just a tad too small on that internal diameter where the rubbing occurs. Tried multiple combinations 1/2-20 bolts/nuts (the original parts had two different bolt lengths and nut widths to hold on the drums) and both rotors on both sides of the car with the same result.

Anyone else had this problem? My best idea so far is either to grind the edges of the head of the bolts down once tightened, or to have a friend get the rotor on a lathe and take off some material there. Neither seem like great options to me.

Yes this is a repeat from the end of my last thread which started out as a different subject. Hoping the fresh post will get some eyes on it.

As always, thank you.