318 head porting for the average joe
When taking max HP affects(this is not, that, of cores!) you are better to go to a 1.50 exhaust valve, to make room for a much bigger intake valve.
Intake air pressure, even in a boosted situation is Way Way, harder to get on top of the piston, then the 1000+ degree and all most, mach-1 air speed being forced out the exhaust. I know i know you say, so make it bigger, to get it out. It just don't work that way. The velocity and the over lap time is what help start the intake moving sooner. You can hurt your intake flow by messing with the exhaust side.
And that is one of the reason why i say Leave the floor alone! and only clean the exhaust port.
Just one mans opinion.