That's equivalent to an economy port. If you look down the intake runner you can see the guide is narrowed a bit. The rough edges have been smoothed and a half a-ed attempt at port matching was done.
Depending on what the numbers were specifically, if they said 270 plus, did they give a pressure drop? Cause it would have to be higher than 28 inches of water. I've done 516's before and they don't flow easily. The exhaust numbers are believable, but looking at the pictures, I'm saying not likely, again, not at 28in.
150 for testing them is not bad. Basically 2 hrs of work. Tear down, clean up and flow. Possibly reassemble depending on condition.
Good lower performance truck, quench heads.