Valve job is factory. My disappointment with this head is the large volume (199cc) and the large throat (93% on a 45 degree seat). The throat was the shocker. I think it's losing a lot of flow throughout the range because of that.
That head with the short S.S. and massive throat is basically unfixable. I find anything over 90% may look good on the bench but underperform on the dyno and even more so in real world part throttle conditions. 90.5% MAX---93%=JUNK.
As for surface finish what you are really doing is altering boundary layer thickness--I leave everything I do AS Carbided, polishing is a complete waste of time and only makes dust. Will customers complain? Probably. If they don't trust your judgement/expertise you don't want them as a customer anyways. I also wouldn't follow what the flowbench says chasing flownumbers based on surface finish. Which finish makes more power?
As for fuel mixing--If your carb/EFI tune is not atomizing the fuel and you are relying on the surface finish in the port to re-atomize the liquid fuel--your problem isn't surface finish--its the fuelmixer/tuneup. J.Rob