1957 283/270hp dual quads drag testing on a 350

[Dragsinger]

while testing, another option is to completely remove the metering rods and change jets to allow the correct mixture.

This is common with Q-Jet racers. [it is called "no rod jetting"] You remove the rods, remove the power piston spring, then reinstall the power piston in it's original location.

Danny Ashley has a formula that will calculate the need jet size. From memory, I "think" the primary jets will need to be about 7 - 8 numbers smaller. Another source of info is Oliver Race Carbs in Arkansas. Both of those builders have extensive experience with all the Rochester and Carter combinations.