Carburetor Advice
Thread Starter
Advanced
Joined: May 2006
Posts: 65
Likes: 0
Carburetor Advice
Hi Guys/Girls,
I bought a 1972 coupe in May last year and it is now time to do a bit of "work" on it. I got 2 motors with the car:
The original base 350/200hp and a 406 crate motor (currently installed)
The original Rochester carb is installed on the 406. I want to take it off and install it on the 350 (soon to be rebuilt).
The questions I have is about the new carb that will be in the car on the 406. I do have a Holley Street Avenger 770 in the garage ready to be installed. Is this carb too big for the 406 crate motor?
When they restored the Corvette in 1998, they had the motor dynoed at 402HP with the original Rochester carburetor.
Just looking for your opinions...
Thanks a million
I bought a 1972 coupe in May last year and it is now time to do a bit of "work" on it. I got 2 motors with the car:
The original base 350/200hp and a 406 crate motor (currently installed)
The original Rochester carb is installed on the 406. I want to take it off and install it on the 350 (soon to be rebuilt).
The questions I have is about the new carb that will be in the car on the 406. I do have a Holley Street Avenger 770 in the garage ready to be installed. Is this carb too big for the 406 crate motor?
When they restored the Corvette in 1998, they had the motor dynoed at 402HP with the original Rochester carburetor.
Just looking for your opinions...
Thanks a million
Drifting
Joined: Aug 2008
Posts: 1,381
Likes: 11
The 770 SA is not too big for 400 cubes. The vacuum secondary set up can be tuned to give the engine just what it needs it the way of air flow - and the great thing about this Holley is the quick change secondary spring set up - you can change the spring to adjust the opening rate in about as much time as it takes me to type this. The q-jet is a great carb also when set up right, and it sounds like yours is, but the Holley can be dialed in to run right with it in the 1/4 mile. If the q-jet is set up right, it should get better gas mileage than the Holley if that is a concern. I have a 770 on a 400 Pontiac and it performs great.
Drifting
Joined: Aug 2008
Posts: 1,381
Likes: 11
They are easy to tune. If you have a new one it came with a CD that covers installation, initial set up, tuning, and troubleshooting. If you do not have the CD you can get it from Holley or you can get all the same info off of their website. Out of the box the 770 will be very close for your 406. I advise looking at the CD, then installing the carb.
Melting Slicks
Joined: Oct 2002
Posts: 2,317
Likes: 111
From: St Louis MO
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski