Piston sleeve lapping reduces break in time by approx 60% and reduces  stress on the engines crank and rod during the break in process  by  reducing the tightness of the piston/sleeve fit.   This is very helpful on very tight engines like Novarossi, Alpha , Arrow and other brands. It is  also helpful  for racers who do not have the time to waste with a very long break in.  (complete engine can be sent in or just piston/sleeve/rod)
 
We have 2 choices:
send in your piston sleeve rod only ( cheaper )
Send in the whole engine ( more expensive becasue we has to take time to dissasemble)