I wish we could have ran that across the engine dyno with a Tim tune job, mine picked up a little over 20hp from a custom timing curve. We saw the same thing with the last 408 tested, it had trick flow heads as well. It's hard to know how much timing it wants and where without an engine dyno since he can adjust timing at every 1k rpm under load to see the changes. I agree with 33IMP about percentage of loss and think the car should show better et/mph than what the chassis dyno numbers indicate.