Classic nock and serving diameter

[Butts2]

I have always just put the nock in hot water and bent it a little to fit on the string. Can I just put a little more serving on over the serving so the classic just fits as is?  

[Charlie Lamb]

You'll get a better fit by removing the old serving and adding strands under a new serving.
(since it seems you have a serving tool already)

You can add a couple strands and serve a small section (an inch or less) and test fit the nock. Repeat until you get the fit you want.