Mopar1973Man

Fuel pressure is controlled by a spring and check ball in the return port of the Fass. AirDog does the same. Now if you can find the right size washer you can shim the spring too increase pressure if needed. As for stability there is a spring mod I do. FASS and Airdog are known to push the checkball into the coil of the spring. So if you bend the last coil over 90° through the center this prevents the check from pushing into the coil causing pressure drop. One project ive gotta do is replace Thor's pressure spring with the new one and modify it too.