I remember Fast making a very similar comment when he tested my Chapman MW 285's. At a certain point the port efficiency for the cross section will give way to port size...this actually makes sense when you consider wet flow and not dry flowbench air. If you have a 12.5:1 A/F ratio for Ideal power at a certain point you limit the amount of port area for both. so while 380 at a 285 cc port area is more efficient than a 310 cc' when you consider a BIGGER motor (and/or 6800-7000+ RPM on a 500 incher) the 310cc port leaves more room to get both the extra needed air and fuel in the holes to make the higher power...it's all very logical. All else being equal the more efficient port will generally make more torque for the given airflow at part throttle and below the Peak torque RPM, but the bigger the motor gets that extra velocity/torque potential is not really even an issue.

The full ported CNC Super Vics seem to flow very close to the Chapmans, and since the supply of Chaps seems to have dried up. Looks like I'll be going to the Super Vics next time around.

What's really lacking in the marketplace now is a suitable low rise Max wedge intake (like the MP 337 or the Indy 2D) that will clear the hood without a scoop.