interesting take on the design ideas.
Mikes Porting Service (highVE) http://www.mikesportingservice.net/
did some development work for me on the EQ350C Vortec replacement heads for rules restricted circle track class. The EQ castings are much nicer and cleaner than the GM906's, although a virtual clone of the 906. These heads outperform the 180CC dart platinum's on the track, despite being considered a 170CC vs. 180 CC intake runner. I believe Mike credits the port design, height of short turn etc...
These are EQ CH350C (vortec replacements) "no porting rule" with 2.02/1.60 (instead of stock 1.94/1.50) and blended within rules. Very careful attention to the blend and the valve job yielded this.
EQ CH350C, 2.02/1.60 "no porting rule"
Lift - I / E
.100 - 79 / 56
.200 - 153 / 94
.300 - 200 /149
.400 - 238 / 177
.500 - 255 / 186
.600 - 266 / 193