1bbl or 2HELP!!

I was in the process of converting my 1bbl over to a 2bbl when i encountered a little problem.Many people have told me that a 2bbl would give more HP and provide a smoother running engine,but about the same number of people have told me not to do this,just replace the 1bbl with a better carter(I am running a holly)What do you all think?Any advise would be appreciated.](*,)