Speedmaster sale. It started

mbaird said
I just watched a video in which a porter flowed a head with those machining marks then polished the ports and flowed again . At some lifts it actually lost a cfm or 2.
Now the cumbustion chambers might be a different story .
I will find the video and post link .

Saw that too.
I’m just going knock off the loose chunks around the guide.
and some smoothing to the chambers. Have no idea in the chamber volumes. Should probably check before any work.

Think the exposed unused spark plug threads be taken down?