FRONT drum to disk

I have got a 73 Datsun 620 that has drums up front. I have 17" Escalades for it...but the center cap doesnt fit due to the dust cap. I took the dust cap off and it still doesn't fit. I was wondering if i converted it to Hardbody spindles and disks, if they would fit. Both are six lug. Also heres the catch... the 620 is kingpin, not ball joint. Any help would be appreciated. thanx