318 head porting for the average joe

the plug boss can be blended some, i have seen heat cracking there...though the crack go's nowhere...but 1st put a plug in and just smooth and blend to its edge.

the area between the int/exh valves can be blended, be careful of corse...
the area where int valve is seemingly shrouded I would leave alone for now.
I have played with that area in the past and it caused ssr loading in that area that seemed to pull the rest of the turn with it and the flow at lift had a blip afterward.

U can however blend all the way around the exh valve on the chamber side and rid the top cut lip.

the port window doesnt really do much for flow, it can stay stock and flow 200-205cfm, its the straight wall & pinch that seem to net more so than grinding a 360 sized window.
You can stay with the 318 window/gasket and just grind the pinch protrusion straight with the windows edge on that side, on the straight wall/divider wall side u can remove a lot from all the way to the bowl, grind a bout .030 out of it, but leave the flange side alone...as in dont thin the gasket sealing surface, go just beyond it.

you're doing a good job btw, and even a lil conservative at 1st glance...which is smart till u flow some of the work u do to know its working.
right on.