carburetor problem
 

Which carburetor would you recomend for this engine https://www.summitracing.com/int/par...make/chevrolet Is this a good one: https://www.summitracing.com/int/par...457s/overview/ I have a 68 corvette. Please link me a carburetor from Summit Racing. :)

This one:
https://www.holley.com/products/fuel.../parts/0-90670

Before you go saying "It's a truck carb!" look at the features......it does not know if it is on a truck or a ski lift.....but I have used this MANY times on 300-350 HP engines and it works great.......I even had it on a hot 347 Ford that made close to 400 horsepower.....
The billet boosters make it work awesome on the street and why Holley does not add these boosters to the rest of their line is beyond me.

Jebby

Thank you :) what do you think of the carb I linked?

The one I linked is based on the one that you linked. Think of the Truck Avenger as the 0-80457 with Adjustable Vacuum Secondary, Billet primary boosters (annular), and a secondary metering block......
The Truck Avenger is expensive.......but I have had the best luck with it as a bolt on with no mods than any other carb I have every played with.

Edelbrock has yet another variation of the venerable AFB/AVS called the AVS 2 with billet primary boosters as well......may be worth a look. I like Edelbrocks on mild engines that make good vacuum but they tens to puke with large cams as the step up pistons get too easily confused. The Edelbrock would work well on that mild crate engine but not my first choice.

You missed the boat in the Parts section yesterday....there was a BRAND NEW Edelbrock Q-Jet in the box that sold for $300......that would have been the unit to use!

Jebby

You will have to change that style of fuel bowl vent tube on that truck carb if you use a drop-base air cleaner, which is common on C3s. The air holes on that vent will be in direct line with the bottom of the air cleaner lid.

Very true.....it could get close in there but a standard drop base with 3" filter does work fine......any lower would get tight. This could be an issue with 68-72 standard hood guys.

Jebby

It has a big block hood. That makes more room right?

Yes....the stock LT-1 small block used a big block hood and it came with a high rise intake and Holley carb from the factory with a drop base air cleaner and 3” filter....

Jebby

Jebby, is there ANYTHING AT ALL about these cars that you don't know? Is that why someone added -san (indicative of respect, great knowledge) to your screenname?

And WTF is a "billet booster" or do I just need to Google it, and why it is such a good thing.

Ha, ha....I do have kind of a lot of knowledge about Vette's as I was Vette crazy since birth...my Mom and Dad brought me home in 70' Vert from Pontiac General Hospital in 1971 :) My Father and his friends had dozens of Vette's over the years and I was right there always, eye open wide.....reading everything I could all of the time.
-san is an honorary suffix in Japan that is attached to a person when thought of with respect...not necessarily of knowledge, although in Japan scholars are respected :) Not like here :(..........many years ago, I lived in Long Island,NY......my name went Jeff to Jebby as I was always at the beach and chicks thought it sounded cool.....a few years after...my good friend Johnny Nova tossed the -san on the end as he was stationed in the ARMY as an escort for a high ranking Japanese/American official......the rest kinda stuck!!!
Believe me though....there are a few people here (Alan is one-WHERE ARE YOU!!!???) who blast my knowledge out of the water.......and that is a good thing.

But on to boosters......I should say "billet annular" as that is what it is......The annular booster has strategically place holes placed radially (or annually) around the inside of the booster halo under the venturi step....most boosters...there is only one hole.....this annular design is much more sensitive to vacuum drop and it is much more responsive on the street..it "signals" better and signal is everything when it comes to carbs.......the downside is that they reduce over all airflow and go pig fat at very high RPM's....(verified on the dyno)......but for a 3/4 effort street engine they rock......

Jebby

If I were installing a new engine, I wouldn't be putting a carb on it. Time to go EFI and go electronic....

I want it old school :)

If you want it "old school", put a Q-jet on it. That's what belongs on it; and it's the best choice by a long shot.

You could go with a Holley Street Avenger. That's what I put on my LT-1 and I like it.

Holley 4175 650 CFM vacuum secondary direct QJet replacement carb..been on my 78 L-82 4 speed since 1985. IT IS A GREAT CARB!

Still on the L-82 355 rebuilt with 425+ Gross HP and runs fantastically.......If you want originality go Qjet.....Want it to run correctly have LARS tune it. Want the easiest simplicastic alternative to a Qjet that will run as well if not better than a quadrajet, the Holley 4175 for these engines...period.

There you go! Lots of choices and lots of [personal] recommendations.