"the bottle rocket"
The ported area is just on the lip that was removed to make them have a 3 1/2 instead of 3. Put the log in a barrow full of water block off one fitting and attach a air line to the other....simple leak check. If the snail is already off I have a piece of aluminum with the 4 stud holes drilled out and put that on with silicone an do the test. I would do a test like this on yours before buying anything. Do you have flappers on your tips?