From my boat...
The mast for my E23 is on blocks in the yard and I just measured the sheaves at 2" flange to flange. That is, it is exactly 1" from the center of the pin to the outer edge of the flange. I believe this is the same as the E25, as the mast section is the same (6.5 x 3.25) and I think the masthead is set up the same too. There is a "double" groove in the sheave, I believe for wire and/or rope.