Paul, Tough call without having hands on, but I would guess the 4.30 gearset keeps the motor up in the RPM range and more throttle opening (less vacuum) for a given situation. With the 2.76 I'm guessing that less throttle opening (and higher load) has the metering rods were bouncing up and down making it run fat. In that situation I'd substitute lighter springs to see if that helped. Not familiar with the Street Avenger but with the old-school Holleys I'd expect a similar issue - we always ran lower power valves so there was no power enrichment until vacuum dropped that low (more throttle). Hope that makes sense - I'm fighting a little flu and am not hitting on all 8... (I feel so... Chevy) SC -----Original Message----- From: Paul Lennemann [mailto:pjlenn@xxxxxxxxx] Sent: Saturday, February 27, 2010 11:20 AM To: 1962to1965mopars@xxxxxxxxxx Subject: gear change & carb ?? I'm currently running a 4.30 SG in my car. I changed to 2.76 peg leg once to do some cruising. When I did I had a problem with the car running way too rich and fouling plugs. I was running a 650 CFM Carter AFB race type carb w/o a choke. I got a strip kit and changed jets and metering rods w/ no improvement. So I just changed everything back to the original setup gears and all. I'm wanting to change gears again. This time either to 3.23 or 3.55 SG. I am now running a 780CFM Holley Street Avenger. Any guesses as to whether I'll run into the same problem? Paul L. '63 Sport Fury 440/727 http://www.1962to1965mopar.ornocar.org/ml-lennemann63.html ---- Please address private mail -- mail of interest to only one person -- directly to that person. I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic. Thanks! 1962 to 1965 Mopar Clubhouse Discussion Guidelines: http://www.1962to1965mopar.ornocar.org/mletiq.html and http://www.1962to1965mopar.ornocar.com/general_disclaimer.html. ---- Please address private mail -- mail of interest to only one person -- directly to that person. I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic. Thanks! 1962 to 1965 Mopar Clubhouse Discussion Guidelines: http://www.1962to1965mopar.ornocar.org/mletiq.html and http://www.1962to1965mopar.ornocar.com/general_disclaimer.html.