Thank you so very much for your very good information and also to question the latter of where the other family came from as I thought. A lot of the ancestral branches are all from the Basse Normandie region. I have found all three of ther marriage records fro Pierre's son Jean Gregoire dit Nantais from the Tanguay Quebec records.
The only source I have of knowing a Pierre Grgeoire and Marie Anne Leveille is from nantaisroots.com and a family tree of Joseph Gendron on the web.
I truly appreciate your kind reply and info.