I really like my installation of my port divider, makes me wish that I had a digital camera of my own so I could show yall. Like I said I used Aremco's Exhaust manifold putty. It was VERY easy to work with. I had the good fortune of a friend allowing me to use the lift in his shop for the install, otherwise I think it would have been 10x harder than it was.
I think when you install the port divider it is important to completely separate the exhaust ports. I am not at all convinced that welding in the port divider accomplishes this. With the putty I used I was able to build a wall behind the port divider that extended back until the head separated the ports, with welding I think there might be a space behind the port divider, towards the cylinders, which is not sealed. This makes the port divider ineffectual.
I am very interested to see dyno readings for this. I really believe that with the port divider installed properly and with engineered headers there should be a goodly sized difference between an engine with and without it installed. I am not sure that header manufacturers engineer anything, it might just be a couple of guys in the shop making something that fits. If the tubes are not of the proper length to amplify the waves then they really aren't much better than having an exhaust manifold. With the port divider installed you should be making a good bit more power from 1/3 of your engine, I would expect that to make some difference.
I guess we will see when the dyno reaults are posted.
-Dan in Atlanta
Also, I just checked and I installed the port divider at 41180 miles and I am now at 44605 miles with no rattle. That's roughly 3500 miles since May and no trouble yet.