legand71

hello new here. got a question for u guys if anyone knows 390 really good i would appreciate the help. i have a 67 390 with 406 big port heads medium riser intake and also big port. a crane fireball 2 296 cam in it and headers on. i am running it in my mud drag truck. it has a 3000 tci stall in too. the issue i am having it that around 3000 it doesnt want to make more rpms. i have a base edelbrock 600 on it. i am thinking its to small of a carb but not sure. if anyone has ideas i would love to hear them. thank u.

kdtrucker

My first guess is that your gear ratios are to high and you may need lower gears. My second guess is that you did'nt dial in the cam correctly.

What is your vacuum reading?? At what RPM does the cam smooth out?? You might have the wrong torque converter.

legand71

Thanks for the input. The gears are only 4:10 and I am running 39.5s on it. The cam was installed correctly also. The cam Smith's out around 1300 if u mean sound wise. Vacuum not Really y sure about. And the stall converter is correct also.

BuzzLOL

.. Ever fix this? Carb. size is fine. Maybe distributor not advancing the ignition timing. Something blocking airflow into carb. 600 CFM carb.s usually default jetted for 302's, may need bigger jets...