I have one set of early (1970) OEM carbs that have been modified to use screw in air bleeds on the outboard carbs. metering plates, choke plate removed on the center carb, still vacume operated. I have had 68 jets in the center carb. with a 4.5 power valve and a .035 power valve restriction channel, the outboard carbs. have had .092 diameter holes in the drivers side and .096 in the passenger side and ran the fastst in my car. I switchd to .096 on the divers side and .102 on the pass. side and slowed the car down. I want to try .094 on the drivers side and .098 on the passenger side next I have not ran it leaner than that, The wideban showed 11.8 to 12.3 with the bigger jets and 12.8 to 13.3 with the smaller jets, both times using Oregon 92 octane pump gas IHTHs