I was using Hughes flow bench numbers for their Stage I port on the Edelbrocks, and comparing it to stock EQ(over 250). Not sure where you got 300 but with very little work, the EQ's will flow 277.
Plenty of head porters can get mid high 290s out of a Edelbrock with some claiming closer to 310. My Edelbrocks went 294 with a 2.02 valve, when they were freshened I had a 2.055 valve put in them. Curtis Boggs did the port work.
As mentioned the EQ head is good for it's intended purpose, but it doesn't have the HP potential that Edelbrocks do.
