i know stock our carbs are limited to about 600cfm total airflow becasue the AV doesnt open all the way. Now if you cut that tab off that is keeping it from opening all the way you can make it support 750cfm. i was thinkin about doing this mod, but i was wondering if 750cfm is to much for my mild 350. what would the PRO's and CON's be of this mod. i was gonna do it so i can put a set screw in there so i can adjust it to what i want. iv already taken care of the rods and hanger issue for fuel (b hanger, DR rods) any input on this mod?

 

750 cfm isnt too much for a mild 350. Q jets still feel like a smaller carb because of the tiny primarys so you would not loose any responsiveness. You can adjust the spring tension on the air valve to adjust the rate the secondarys come in. Doing this will help you get more flow on the top end. More flow = more power.

 

iv already done the AV tension mod. i just wnated to know between 600-750 ...what would be better.

 

That's the thing about a q-jet - with the AV tension adjusted properly, it will never flow more than the engine can use. So, if it can use 625 cfm, but is limited to 600 by the tab, it would be an improvement to increase the capability to 750, even though it would still only use 625.

 

alright, ill do the mod and see what happens when i test it out.
thanks.