Mechanical secondary or vacuum secondary carb for daily driver

[dickeymoore]

I have a 1979 Chevy Monte Carlo with a small block 400 with upgrade Parts I'm running a Holley Street Avenger 670 vacuum secondary carb now and the carb is giving me problems this is my daily driver car will it be too much to put a Holley ultra 650 double pumper on the car and it still be a daily driver and advantages and disadvantages for the double pumper?

 

[Michael Watts]

A vacuum secondary carb works a whole lot better on the street.For driveability and for fuel mileage as well. Compared to double pumper of which is more of a race carb.

 

[fleming442]

If it was a stick, you could short shift it. A vacuum unit for a slush box..
Oh, and have you read the destructions and started over? I learned a lot reading the manual for my Speed Demon.

 

[565bbchevy]

Dial in the Street Avenger and you will be fine.

 

[spidereyes455]

Puddle dumpers suck on a street car. Once upon a time I put a 650 dp on my 71 lemans cause I just had to have a 4bbl on it and that was the only good 4bbl carb I had at the time. It was worse in every way than when it had the original Rochester 2G on it. It took forever to warm up and was a b*tch to start cause the choke didn't work the throttle response was terrible, and no matter how hard I tried it always ran way too rich and just was no fun to drive even though it had a 4 speed and not an auto.

 

[pagrunt]

I've had my Holley 4165 with vacuum secondaries on the old 305 with the Saginaw behind it & everything was always smooth with acceleration regardless how light or hard I was on it. Easy cold weather start & go. It's on the rebuilt 350 for when it goes back on the road.

 

[500/600]

If your engine has enough low speed torque to stay out of the secondaries, then double pumper. All others use vacuum.

You just aren't going to take the advice given to you in your other threads and straighten out the one you have? The main downside to a Holley 650 Ultra is that you'll be spending north of $600 for no reason, instead of a maximum of $30 for a rebuild kit...………………...and you'll still have 650cfm.

 

[pontiacgp]

and then there is always a Quadrajet......🤔

 

[DocG G-edi Master]

Ok here goes nothin, I too have been down the Holley Highway to Hell. Same scenario, Small Block Chevy on the street, Vacuum then mechanical with no improvement and a lot more wasted fuel[mileage and fouled plugs] So I finally invested in a Holley Performance book and Wow did I learn a Bunch ! Specifically I learned that every model carb Holley or Quadrajet have their own idiosyncrasies [ engineered in problems]. It was enlightening to learn and fix my own carb , which by the way lead me to helping many others do the same. I wish I still had this book. Lent it to another Body man I worked with in Tampa and that was the last I saw of it. So if you have the time and want to learn some Good Stuff try buying the latest copy of the Guide to Holley Cards.
Best of Luck to you.

 

[gnvair]

The Brawler series of carburetors are VERY nice for the money. You might want to look into them.