[Don Macdonald]

Kinda at a loss here. My air injection pipe ( manifold) has rusted through and I managed to find one on the net. It arrived and was the correct fit for my 1973 Cadillac Eldorado 500CI GM part#1602996. When it arrived I noticed a very rough crimped area with some sharp edges near the diverter valve area. About 3/4 of the diameter in this area was crushed and about the same in length . It looked as though someone dropped something on the pipe or squeezed it with pliers. Since the original pipe did not have this crimp I questioned the seller. He informed me that it was a factory part that was updated to increase airflow. He also claims to be a Cadillac dealer and will challenge anyone who disputes his claim. I would think if it was a factory update the tube would have been finished as it might be from a machine shop. I have been involved with cars for over 50 years and really question his claim. I am looking for the truth in this matter and would like to know if this is a updated method to increase air flow by crimping the original pipe) I have photos of the part as purchased. Sorry failed to upload to this site.