Disappointing ET's with 408

I agree with DusterDon & GTX on lots of this.

600 goes bye bye and make sure delivery is adequate... it's like making a runner do a marathon breathing througha drinking straw. You can do it with a good mechanical as long as the feed line has ample volume.

Get an 850 or 950HP carb. Is got a roller in it!!! That thing will eat up carb. At least put the PF 750 on it. That's still to small for the combo, IMHO

What were the incremintals and trap MPH on the run. 60' 330' etc. The overall ET really doesn't mean anything.

The small tube headers are definitely holding it back. You don't want to ask me about tti headers... that's a meltdown waiting to happen. If it's primarily a street driven car, the tti's are fine. If it's a race car, LOOK ELSEWHERE! There are compromises to be dealt with. That header comparison for your engine is not really valid.

All timing should be in by 2000-2200.