CSOM - how to load query that compares default project field to a custom one

hello forum members,

i am new to CSOM and i am trying to figure out how to bring all projects where a default project field of 'Owner' is different from a custom project field of 'PreviousOwner'  and i am having very hard time figuring it out.

here is what i have so far. 

var pro = projContext.LoadQuery(projContext.Projects.Where(p => p.Owner !=  CustomFieldValue here ))

i know we can use custom fields like so - Custom_3f8d5e32535de51180fc0050569d591d, but i cant figure out how to use it inside the loadquery statement. 

tatiana