Hi Josie,

Welcome to the forum! I’m surprised no one has replied yet, since there are some who are actively researching the Plasencia, but they’re likely away for the holidays. You might want to check through the NuestroRanchos archives, you’ll find various threads on the Plasencia and your other lines, maybe you’ll find your ancestors.

I do have Plasencia in my lines, but way back, in my maternals, so my research hasn’t gone passed 1700. I do know that almost every family group had a son named Pedro Plasencia, which makes it difficult!

I did a quick check on your Francisco Xavier de Rubalcava and Maria Francisca Sanchez. If you don’t already have this, here’s the dispensation for their son, Marcelino de Rubalcava, for his marriage to Anastacia Plasencia, 14 Apr 1779, Yahualica. They are are 4/4 consanguinity, being great grandchildren of siblings Miguel and Maria Gutierrez de Hermosillo, who were children of Pedro Gutierrez de Hermosillo. This will get you back a few generations:
https://familysearch.org/ark:/61903/3:1:9392-6VCG-C?mode=g&i=587&cc=187…

Anastacia Plasencia had a sister named Ana Gertrudis Plasencia, who married Marcelino’s brother, Joseph Antonio Rubalcava. I haven’t pulled their marriage partida, but I’m sure it says they were dispensed at 4/4, too. The girls were daughters of Joaquin Plasencia and Maria Manuela Alvarez de la Cruz. Siblings marrying siblings, which was common with many of these families.

You’re exploring the right parishes - Cuquio, Yahualica, Nochistlan. You might want to check Tepatitlan, since many of these families lived there, too.

Saludos!
Manny Diez Hermosillo