27 should be okay for a C to D connection. I did a slight jog and made it from D9 to B12 in 11 minutes with a trip to the restroom tossed in not too long ago.

Delta also seems to have some extra padding in their turns.

BTW, when you come back do you clear US customs in SLC? SLC was amazing in clearing when I did CDG-SLC-LAX last year.