The OP said he's refitting a Schwinn -- probably has an Ashtabula now, and he's thinking of using that conversion kit to install an English threaded BB into a Schwinn "big hole."

To Stringbreaker: there are a lot of moderately-priced Japanesey cranks available on eBay, some are even Campy clones, like the Sugino Mighty Competitions. I think that hubris/sacrilege would be totally avoided (though a rabbi should be consulted about the specific laws that apply) if one used a Nippon Campy clone with S 105 FD.