Thanks, and yes, it does take a steady hand with the correct burrs, but compared to the iron Pontiac heads I'm porting this Aluminum BBC is a walk in the park LOL. The bowls are in the 91.5% range. The head is actually marketed and "sold" as a 320cc runner with 126CC chamber, the chambers are correct, and after my work port work, the intake runner (#1) came in only at 315cc, but that's OK.The #3 may be larger. Now hitting the 360-370cfm range now, sound nice, and good port speeds, that should be OK to support the HP goals for this customers needs/demands and build details. I am dyno tuning a new carb I built for a new 489 BBC build from another shop, single cast 4bbl intake with these exact heads in the next few weeks, we will see how they perform and if the flow numbers translate to the dyno. Nice thing is the owner goes to the track, so the MPH will tell the tail.