Care to speculate my 340?

I'm with Rick to a degree. I do think the desk top dyno is really in the ball park.
While reading the thread, I was going to guess 320HP at her best running. A Header would be a real plus. The choice of TTI's would be for me though the headers by Doug would be fine.
Someone said an extra 30HP with headers. I think a little more myself since you get 30HP from a stock engine. Same with the ported heads. Speaking of which....

IMO, is leave the X heads alone and move to an after market head. Between the all the heads out there, it's really up to you on how much of a ceiling you want to have. Focus on the area of curve on the air flow.

Your going to have a nice strong street runner when your done.