You can merge surfaces together:
Duplicate both surfaces. They will not be under the influence of the SCM, but will keep the same shape as if they were.
Move slightly away one surface from the other.
In Single-select mode, select one surface, Model > Draw > Merge Surfaces
Pick the edge of this surface that is to be merged,
Pick the edge of the other (the surface is unselected, but the tool will allow you to pick the edge without selecting the surface. Just click as close to the edge as you can).
There you go.
Hope this helps
Salutations - Cheers
Bernard Lebel