So another member (ewwirth) was wonderful and sent me pictures of his floor with a tape measure in them.
His center main floor panel is 20" long to the top of the lip.
Mine is 18.5" long to the top of the lip.
Apparently, there we different size opening in different years.
Thanks guys, I will be adding 1.5" to my floor panel this weekend.
Thank you so much for taking the time to send me all the pictures.
