I have a Grant wheel somewhere with a plain Tuff wheel center on it I'll see if I can find it and measure to see if they are the same.
Sorry it took so long to get back to you.
The switches are the same height, 1-1/8"
The cap to wheel gap is the same on both wheels, 1/8" with the standard cap on either wheel and 1/4" with the fish cap on either wheel.
The gap is filled by the foam on the fish cap though so it isn't really noticed.