I was wondering if any1 knew the approximate cfm of a carter 2bbl carb on an 85 fifth avenue. im switching to a 4bbl but didnt want to go with something too big. i figured maybe a max of double the carters output. all that ive done to the car is put headers on it and a performance ignition. i was told 600 cfm would be way to big without a cam or other mods and was just wondering if any of you guys had an opinion. i also have aset of 15 inch wire hubcaps in decent condition if any1 is interested.

 

Im gonna guess somwhere between 300 and 350.
for the carter 2bbl.
Vacuum secondary 600 would be fine on a 318.
Use an edelbrock performer manifold.

 

i was told that 600 would probably be too big on an engine that mild though. any idea what they used on the service model diplomats for the 4bbl. i already have the intake. i got a holley street dominator off of ebay brand new for 50 bucks including shipping.

 

i read that going to big would drop throttle response and bottom end torque

 

holley makes a real nice 390cfm, carter/edelbrock has a 500cfm

 

I was going to say, if the 600 is too large then Edlebrock makes a 500.