Torque Converter to Flexplate
I have a buddy that is assembling his 502HO and his TH-400. He too has a TCI torque converter, but here is his problem. Obviously the holes on the converter and the flexplate line up, but the holes on his flexplate are too small for his bolts. He asked a local Chevy service department trans. mech, and the mech said to drill or ream the holes out to fit the bolts. He said that this isn't a problem, nor will it cause any. It is a 168 tooth flexplate and yes the converter is for it.
I didn't know how to answer this, because I have never ran into it before.