Jose Manuel Romo de Vivar and Maria Gertrudis Loera

I need help in finding the parents of Jose Manuel Romo de Vivar and Maria (Gertrudis) Loera. I have been researching the line of descent of their daughter Maria Micaela Romo de Vivar. Maria MIchaela was married in 1779 so this places Jose Manuel Romo de Vivar and Maria Loera as being born in the early to mid 1700's. Maria Michaela Romo de Vivar did marry another Romo de Vivar but the marriage record states that a marriage dispensation was not needed. This Romo line eventually leaves the Aguascalientes area and moves to Coahuila.
Thanks,
Rick A. Ricci