I dont follow u on (making each cylinder exactly the same) ?? U refering to the heads ? Also I agree with you, so port matching, polish, and blend, Don't reconfigure the ports correct??
Kindof unsure where you're going with this Dave, but No, every port should not flow the same or carry the same charactaristics in almost every application I can think of. You already know this. There's a huge difference between porting and simply "hogging out" existing ports, which is exactly what most CNC operations do. My 429 D2OE's cost me a touch over $1700 to have them manally done, the D3's later, a little south of that as a favour. This is a VERY "per case, instance, brand and application" based question. I also like Ralphs VERY valid point, "We don't race flow benches here".........I'm not a porter or expert, BUT.........
A TON of additional information would be needed for any qualified porter to do his thing. First example, would be Brand. BBC's fire order is 1-8-4-3-6-5-7-2 and given that order, I would see more attention to the distant corner intake ports, depending on manifold. I would also see more attention need on the center exhaust ports and header tuning to control the exhaust pulsing. On a BBF, 1-5-4-2-6-3-7-8, a very different situation. I can see it being more of a bank to bank issue because the passenger side banks have already fired off 3 cylinders to the drivers side one, before #6 is fired off, and vice versa. Therefore, my mind, and kinda what was done to mine, would tell me that 1 and 5 needed less work on the intake side, more on exhaust, and the real focus point should be on 7-8 on any given head but also relegating those heads to specific Driver or passenger side in that extreme.
This isn't taking into account displacement, what exact heads, etc, etc.........Personally, I see "CNC porting" as more a gimmick than a real life performance improvement. Unless said, reputable, shop does it's "CNC Porting" oh VERY high quality equipment (NOT an old, used Bridgeport) based off measurements from a reputably done and proven set of manually ported heads, and knows exactly how to do this properly using Unigraphics or similar, you'll wind up doing more harm than good, no matter what the port size or flow numbers say. Fast ain't cheap and cheap ain't fast, and again, plug readings alone would help tell the real story as to what was needed an if it worked or not.
In other words, you cannot make a 900 HP 454 BBC using CNC ported peanut heads...........EXCEPT on Ebay.........
Ray