I have a 509 purple cam in my 340 Duster and she idles at 1400 RPM and of course with that cam you will need at least at the minimum 2800 Stall. I have a 3200 Stall and have no problems. I at one time thought that my idle was too high and in lowering it I had stalling issues so I went back to 1400.. Another thing that you may want to look at is an electric fuel pump with a regulator set at 9 psi... JMO...