Rick; Glad to see this isnt turning into a flame war. Lets keep it that way.
As for the Cobra turning 464hp, I still must see that. I have seen 2 2001's and a 2002 Cobra dyno, and the most I saw at the wheels was 290. So if you are talking 464 rwhp here, something is wrong. That kinda of hp gain is only seen with other bigger mods (ie. heads, blower cam, etc).
As for my bud with the 98' LS1, he has a Vortech blower with the aftercooler. He is the one running 9 psi. He had it dyno tuned, which basically consisted of adjusting his air/fuel mix, and his timing advance. Thats it. I can try to contact him to get his dyno numbers. To be truthful I dont have any idea what they were.
And for the engine differences; you are correct, the DOHC Cobra motors are unique in that aspect. You have to give credit to GM for updating a pushrod motor to stay ahead of the new modular wave brought by Ford. Each of these motors earn respect in different ways. To be honest with you, I am happy to see the later 4.6's running closer in their battle with the f-body's. You know as well as I do the f-body has dominated since 93. Just like the Fox body had its own before then. I have all kinds of respect for the newer Cobras, and even slightly modded older ones.
Like I said in my previous post, link me to your "464 hp " figure on a STOCK motor. I am normally not a disbeliever, but you got me here.