If you ask super nice they will serrate them.
The 766 brush is awesome. I have not done any 4 cell testing with them but running them against 767 brushes they the same if not more power and are much more durable. They stand up to harsher conditions. The XXX is a great brush for longevity and will probably last longer over all but they do not produce the power in my stock testing.
The serrations last a long time on the 766. It takes about 5 6-8 min runs in offroad 6cell stock to wear out the serrations. In a 767 it takes about 2 runs.
The brush is harder like the XXX so the serrations last longer. The serrations are not overly deep.
James. Serrations are the ridges on the face the brush. Serrating was something you had to do yourself back when you used to race. Now most all race brushes come serrated. I would recommned 766 brushes for you since you do not have a lathe yet. The brushes will last longer between cuts.
