I will have to do something. My 360 is not close to being done, but I will have to do something. I have thought about drilling and tapping the bolt holes on the convertor, but I don't know how safe that is.
If there's enough meat there you can do that but some pads aren't very wide and can't be tapped that far and still retain strength. Do some measuring and see how it looks. Another thing you might do is take the flex plate to someone that can accurately drill a set of smaller holes. That would actually be my first choice. If you have a good drill press and carefully make a template you can probably even drill the holes needed yourself. Just make sure you get them exactly right on or it'll chew things up from wobbling.
The B&M plates in the Summit link posted have both size holes so you choose which bolts to use.