Hey guys, trying to get the tune just right on my Holley carb. Let me tell you what I have so far...388w with afr185 heads and a 238 degree cam and a 2500-2800 rpm stall. It's a 750 cfm double pumper. Read David Vizard's book and it got me pretty close. Running a 67 jet on the primary and 80 in the secondary. I have an autometer wideband on the car and cruise is a nice 14.0 to 15.0 and that makes me happy. Had to put a 50cc accelerator pump diaphragm and the yellow pump cam with a #40 nozzle - finally cleaned up a gas pedal stab and my AFR doesn't go lean or stumble. Part throttle was pretty bad at first, would go super lean at about 25-30% throttle - 17.0, so I went from a 4.5 power valve to a 5.5 valve to a 6.5 valve and even now it still goes up to 16.0 briefly and then cleans up to 14.0 and keeps falling to wot the car runs 12 - 12.5. Any suggestions? If I cruise or go balls to the wall then it runs very clean, at part throttle is where my issues is.