My 302's would be lucky to measure 140 cc's in total port volume. GTX Johns would probably be around 125 cc's and they don't have any problem making his 4000 pound station wagon run well into the 11's. He's doing far more with less.........All the more impressive considering he's using 3/8 valves too. Now consider he's limited to a stock cam lift.....Its a miracle that engine even runs its that restricted.
The difference between the port entrance of the Air Gap and the Street Master is HUGE. Yet the Difference in what the engine made at 5600 RPM wasn't. If the engine was airflow starved it would have picked up a lot more power in the swap but it didn't. That tiny port opening wasn't that much of restriction after all.