Kolakowski / Kulakowski family in and around parafia Bogate and Baranowo

I'm researching the Kołakowski family in and around parafia Bogate and Baranowo. I've found several records of Jan Kołakowski & Jan Kułakowski. Both are the same age in 1849 and are married to a Jadwiga. I have an idea they are the same person but am not absolutely sure. Were the names interchangeable back then? Thanks for any help.

Noit interchangebale but illiteracy was high, hence spellings often varied. Both names exist in Poland, probably toponymics from Kułaki or Kułakowice and Kołaki or Kołaków resepctively.