318 head porting for the average joe
With these 318 heads..the only way to screw up with air speed... is to ruin the short turn/cut it out or lay it waaaayyy too far back.
360 heads flow way more and are a diff deal, dont worry about it with ur 318 heads.
If u do as i show, you'll be fine.
btw...the guide boss shaping was an experiment, i have another port on this head where all i did was lower it's height...but left it's length and width...and it does 207cfm @.550. I was just doing this to show what that would effect.