Spreader Length
 

I'd like some guidance regarding shortening the spreaders on my 1952 47' S&S yawl (sitka spruce spars). Like many boats of this era, the width across the (single) spreaders is slightly greater than the width at the chainplates. I assume that this was done in an attempt to increase the cap shroud angle at the masthead, but my reading of "The Rigger's Apprentice" and conversations with designers and riggers suggests that any gain due to an increase in cap shroud angle is more than offset by losses due to increased compression across the spreaders and torsional instability of the mast.

The simple question is: does it (?ever?) make sense to have the width across the spreaders greater than the width across the chainplates?

Here are some details of my boat:
single spreader, fraction rig with jumpers
half-width at spreaders: 54"
half-width at chainplates: 50.5"
spreaders to cap shroud attachment: 268"
cap shrouds 3/8" 1x19
mast is 6 years old, sitka/epoxy construction, built according to original S&S design

According to my calculations, this gives a cap shroud angle of 11.39 degrees. I am thinking of shortening the spreaders by 3-4 inches, and am looking for some input regarding whether this is safe, and/or how I might go about getting a definitive answer. As an example, if I were to make the width across the spreaders equal to the width at the chainplates, this would result in a cap shroud angle of 10.77 degrees.

Thanks in advance!