I spoke with my customer the day other on this set of Stealths I have in the shop. From our original conversation I had assumed he was only looking for the "bowl blend" level of porting done to these heads. After our conversation the other day he indicated he was more interested in having them flow solidly in the 280's+, so I went in and opened the pinch to 1.140 and trimmed the guide boss and the port roof adjacent to the boss. This is the same port as the other two tests from earlier(#1).

Lift------intake flow
.100----71
.200---146
.300---211
.400---254
.500---277
.600---285
.700---290

Here are some intake port volumes to give an idea of how much work is involved to get from one level to the next. I didn't check the OOTB port volume, but the bowl blend only removes a couple of CC's worth of material.

Recut seats, blend bowls = 210cc
Open pinch to 1.140, narrow guide boss = 217cc
MCH full CNC ported and valve job = 252cc

On an Edelbrock head, if you do a basic port and polish it'll flow right at about 300cfm, and those ports are usually in the 228-230cc range.