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Its not just about flowing for your power goal.

Its also about effecting drivability.

Bigger ports can hurt flow speed, hurt lower RPM power, in the hunt for high RPM power.

Where you take off can make a big difference, you dont just hack into it with a die grinder.

Walls are already thinish, take off too much from the wrong place can make you head worth its value in weight of aluminium when you break into a water jacket.

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The 25 head I built for our circuit car had only very minimal port work. All I did was clean up the ports which was pretty well just some blending into the throat below the valve seat. That head had the supertech kit through it, solid lifter conversion and 1mm oversize valves. That engine was making 680rwhp on a 3.4l stroker with a gtx35r.

From what I have seen, its really only needed if you are shooting for mega power; 800rwhp+.

As everyone else has said, money can be easily spent on other things first!

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