sorry i went 12.4

 

1) You didn't answer my questions.

2) He shouldn't have another 3-5mph, he should have more power, which results in higher mph. For his "POWER LEVEL", he is running good times and trapping well.

 

Cool, no problem.

I'm not trying to be a jerk, just trying to make a point .

 

well to the OP= if the car put down 320 rw with lid & catback only with those heads then they were performing up to par . rwtq looks inline as mentioned so i would look into a couple things =
what octane gas are you running ?
the tuner may have got knock and not put in enough timing in the upper rpms,i would think around 28* or so at peak hp should be where it needs to be.you could of had less than stellar gas in the tank when dynoed also.