Anyone ever have their heads ported and polished, if so what kind of numbers can one expect to gain?
On sub 700 rwhp cars I will go out on a limb and say that 90% of whatever gain was recorded, if that was the only mod(which is practically never) was gained from the freshened valve job and the tight new guides.
Yes I'm serious. If I was doing it I would spend the money on guides and the required valve job after the guides and that's it.
You don't want the intake port polished anyway.
Now if they had ceramic coating available for the exhaust ports and I wasn't running cats, I would be all over that. It would be nice on the piston tops and combustion chamber too, along with some kind of piston oiler jet machined into the connecting rod.