Here are the specs for the O'DAY 25 Standing Rigging: Wire diameter is 5/32" and the DWYER Mast catalog that I have listed the clevis pin dia. for the turnbuckle for that size wire as 5/16".
Standing Rigging Specs.
Headstay 5/32” x 30’10” (K/CB)
5/32” x 32’10” (Keel)
Upper Shroud 5/32” x 28’9” (K/CB)
5/32” x 30’ 9” (Keel)
Lower Shroud 5/32” x 15’8 ½” (K/CB)
5/32” x 16’8” (Keel)
Backstay 5/32” x 32’8 ¼” (K/CB)
5/32” x 34’8” (Keel)
All Standing rigging is SS 1x19 type wire and lengths are with turnbuckle (where applicable) closed, from eye to eye (most riggers measure with turnbuckles half-closed, so be sure to note this and/or bring old rigging to rigger to measure for replacement)