sould like what i'd do if i had one 
750 Holley on a ZZ4
Race Director
Joined: Mar 2001
Posts: 11,322
Likes: 1
From: Living in the Hartland
I have a 600 vac sec holley similar to your 670 street avenger and when I put my 750 dp on my 350 it felt like a shot of nitros and I had the sec's unhooked to tune the primaries. 
Race Director
Joined: Jan 2003
Posts: 15,176
Likes: 88
From: State of Confusion
Not a ZZ4, but I run one on my 355" Z28 drag-car.
Some peolpe think a 750 dbl-pump is too big for a 350" SBC, but it made my Z both quicker AND more consistent than a 650 dbl-pump, and we'd tried everything making the 650 work...
Some peolpe think a 750 dbl-pump is too big for a 350" SBC, but it made my Z both quicker AND more consistent than a 650 dbl-pump, and we'd tried everything making the 650 work...
Team Owner
Joined: May 2001
Posts: 29,745
Likes: 3
From: Exiled to Richmond, VA - Finally sold my house in Murfreesboro, TN ?? Corner of "Bumf*&k and 'You've got a purdy mouth'."
CI 6-7-8 Veteran
CI-VIII Burnout Champ
St. Jude Donor '06-'10, '13
I personally think a 650-700 CFM is about the right size for a square bore on a mild 350. I would like to see a spreadbore in a 750 CFM. That way you get the throttle response of the small primary bores and the atmosphere sucking power of the larger secondaries when you need them. The larger primaries on a 750 square bore carb seem to loose the punch and low-mid range throttle response and always seem to be a bitch for tuning.
Melting Slicks
Joined: Jan 2004
Posts: 2,672
Likes: 1
From: New Cumberland PA
Originally Posted by Glensgages
Not a ZZ4, but I run one on my 355" Z28 drag-car.
Some peolpe think a 750 dbl-pump is too big for a 350" SBC, but it made my Z both quicker AND more consistent than a 650 dbl-pump, and we'd tried everything making the 650 work...
Some peolpe think a 750 dbl-pump is too big for a 350" SBC, but it made my Z both quicker AND more consistent than a 650 dbl-pump, and we'd tried everything making the 650 work...
In my opinion a 750 may be to big for some 350's, but a good choice for others. It all depends on what mods are done, how it's driven, and if a few more ponies are needed ant the top end.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
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
Burning Brakes
Joined: Jan 2004
Posts: 769
Likes: 0
From: Ft. Lauderdale Fl
Hay Ken, 
I put a 750cfm mech secondaries on my ZZ4, 385 fastburn And I love it. But, after driving for a couple of days. I found that I was running a little rich. and chugging/coughing at mid to high RPM's I changed the secondaries from 80's to 78 and now she pulls great al the way across the board. Some old timers told me that I would have problums with the DP loading up. Maybe in 1970 they had that problum. But, I haven't had any trouble. 
I put a 750cfm mech secondaries on my ZZ4, 385 fastburn And I love it. But, after driving for a couple of days. I found that I was running a little rich. and chugging/coughing at mid to high RPM's I changed the secondaries from 80's to 78 and now she pulls great al the way across the board. Some old timers told me that I would have problums with the DP loading up. Maybe in 1970 they had that problum. But, I haven't had any trouble.