I was wondering if there is much weight difference between 23/64 and 11/32 cedar shafts.
On average, 23/64 will be about 40-50 grains heavier for a full length shaft. However, there is some overlap. For example, for a given spine, the heaviest 20% or so of 11/32 shafts will be heavier than the lightest 20% of 23/64 shafts. That's why suppliers bundle shafts not only according to spine, but also according to physical weight.
In the middle ranges, of course, you could get the same spine and weight shaft in either diameter shaft. For example, 390-400 grains and 55-60# is fairly common in both 11/32 and 23/64 diameter shafts
Of course, because of their larger diameter, 23/64 can also be found in higher spines. 75# plus spines in 11/13 are fairly rare. Much easier to find 23/64 in spines from 75-90#, although they, too, are becoming more difficult to find on the higher end.