Im with Joe and Brandon. Rich LSN and too big of an idle gap. OS engines are set like this from the factory so you run plenty of fuel through them when new and they wont stall constantly but as it breaks in the idle starts to climb because its not so hard to rotate the engine.

Whats happening is the idle gap is too large so coming off the high end it stays at high idle until it starts to load up then the idle comes down.

Set the idle gap to about 0.5mm then lean the LSN out. This should get you back in the ballpark. Then make sure the HSN isnt too lean which is common when the LSN is too rich because when the LSN is rich the temps come down significantly which usually leads people to lean the HSN out too much.