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Got a stock 454 or close to stock Needs a carb. Would a 750 Holly with manual secondary be ok Or is it to big. Don’t want nothing to big.
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What intake you got?
A quadrajet was 800 cfm for a big block.
A custom quadrajet is comparable price wise to a Holley 750.
Both to be found here.

Personally ,I'd rather have the Qjet . Best street performance carb ever !
 

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Got a stock 454 or close to stock Needs a carb. Would a 750 Holly with manual secondary be ok Or is it to big. Don’t want nothing to big.
750 holley with vacuum secondary would be better.
Q Jet would be Ideal
Quickfuel would be the way to go if you dont have a carb yet.They are easier to tune than a holley
 

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Using a double pumper carburetor from Holley or Holley style carburetor will need some requirements vs a vacuum secondary Holley in order for it to operate correctly on the secondary side opening. A double pumper needs quick rpms and a vehicle that is light and not something heavy that takes a bit to get going as a double pumper when hitting the throttle and you end up opening up the secondary side of things, without quick enough rpms to get the vehicle moving it will be a big bog and a real soggy signal catching up with the load on the engine.

They can work with vehicles that can get rpms up quickly in the rpm band of its said build and camshaft rpm range and also if setup correctly. It can be used on automatic transmissions and does not need some high 3000 plus stall convertor like Holley recommends as I have used them many times on a th350 using just a 2200 stall convertor and 3.42 rear gearing. The success is my truck could hit the rpms very quickly and pick up speed without any lugging.

A vacuum secondary Holley like mentioned would be the better choice as it can be made to open up to demand as it goes by air velocity as does a Qjet carburetor. The Quick fuel brawler 750 carbs would be a good investment if you want to go that route and they have an adjustable vacuum secondary pod that you can control the rate it opens up. With a double pumper if its not sized or tuned correctly its not very forgiving. With you having a big block a 750 would be more then enough for it but the style depends on the setup such as your rear gearing and the vehicle weight and how quick it gets up to speed and other factors.

You don't want to end up with a band aid tune on the double pumper with a 50cc secondary pump shot size to cure a massive bog because its not the best choice for your vehicle. I have seen many times folks can't get one properly tuned because its not the right carb choice for there ride and end up with band aid type of a tune such as a big 50cc pump shot on either the front and rear both on the pump shot circuit. A Qjet will give better mileage and overall better results as far as being the best fuel metering but a Holley will give more performance if a more performance oriented build.
 

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The accelerator pump nozzle size & pump can determines how much fuel is delivered ,the accelerator pump size insures there's enough fuel for them . If your getting enough fuel with a 30cc pump , a 50cc pump won't change anything , other than buying & installing it .
 

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All I meant was folks who put a double pumper on a vehicle that was not equipped for one, because of the way the secondaries would open so fast hitting wide open throttle and in order to cure a massive bog because of the secondary side opening up to fast and no way of adjusting it in relation to demand from the engine, folks have used a bigger pump 50 cc shot because the normal 30cc size and shooter size and pump cam combo would not be enough to cure the bog coming from the opening of the secondary and sometimes with the combination of the front coming into play so fast at wide open throttle.

A 50cc is going to give more fuel over a set amount of throttle travel vs a 30cc. Just saying putting a double pumper on a vehicle that can't take it will end up with a band aid tune job at times if its too big and not size correctly and put on a build that is not equipped for one. Have seen it and read about it many times. Not saying that is always the case but they are not just able to be thrown on any engine and work just fine. Holley double pumpers will open up fast when hitting the throttle regardless of the vehicle its put on. That is why many who have put them on builds that they should have not been stuck on the first place always have complained of horrible bogs and end up with a way out of proper setup with the pump shot on them. Just an example on what I stated.
 

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A stock 454 would get along just fine with an Edelbrock AVS either 650 if your a cruiser on the highway or an 800 if like to curl your toes over the speed limit.

The AVS is as close as you can come to the Q-Jet from current domestic production carbs. It uses metering rod primaries as does the Q-jet with an adjustable air valve in the secondary so no matter how deep your into the throttle the air valve will not overflow the engines ability to digest mixture as a mechanically linked Holley or Holley clone will do.

The AVS can be found in two variations the AVS1 which is the older original Carter Carburetor design (1968) and the Edelbrock redesign of that the AVS 2 which uses annular booster venturies to replace the original single vent down leg booster. The annular stirs up a more uniform mixture for the engine making for better gas mileage and smoother cruise RPM operation. The cost is a little off the top end but this doesn’t sound like a place you operate at but if it is the 800 is large enough to cover that and then some. But for moderate legal speeds an not bury you foot acceleration probably the 650 is adequate.

Dont confuse AVS Thunder series with the AFB Performer series. The Performer is the older of the Carter original designs (1957) it mostly differs in the secondary where it mounts a velocity valve that is not adjustable and is positioned under the secondary venturies and their throttle blades. It’s a decent carb and except for the secondary air metering valve is mostly common to the AVS.

Bogie
 

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I second what Bogie said. I always forget about the Edelbrock AVS2 series of carburetors and if running something stock it would be good and easy to tune and more efficient then a Holley style. If your willing to run something different but if you want to run a Holley I recommend a 750 vacuum secondary Quick fuel brawler as it will have more tuning features and adjustments vs a Holley brand equal and tune for your build.

All depends on your preference. The AVS2 would give the best mileage and be good for cruising. Listed below is a Quick fuel 770 (750cfm) brawler which is a 4150 since it has a secondary metering block and the 750 Quick fuel slayer which is a 4160 since it has no secondary metering block but it has secondary jets but you can't change anything on the idle circuit wise on the metering plate. Then the Edelbrock AVS 2 800 and 650.






 

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Something else to consider if you choose an edelbrock carb. You might also need a heat spacer (tendency to boil fuel) and a fuel regulator(pressure sensitive and limited to 5psi).
‘And throttle and trans hook up brackets are sometimes difficult to hook up.
All added expenses.
 

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what car is yours? I have a 1985 C30 crew cab with a 454 modified with dome pistons and a performer rpm cam, stock exhaust manifolds and intake, I had the stock q-jet that finally died so I installed a spread to square adapter and bolted on a stock Holley 600 cfm vacuum secondaries, I could't be happier, performs great, starts like EFI, awesome midrange (where I drive the most) and even decent on top wich is not much above 5.500 and even gets pretty decent gas millage, there is no way I would install a bigger carb, I don't want a race engine, it's an almost daily driver that I use for work, it releases the torque beast that the 454 is built for. the only changes I've made so far are recurved the distribuitor and installed 68 primary jets. Bigger is never better, even for racing.
 

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Got a stock 454 or close to stock Needs a carb. Would a 750 Holly with manual secondary be ok Or is it to big. Don’t want nothing to big.
I have a Holley quick fuel 750 / elect choke vac secondaries on my 396, a mild street build and I have an AED performance 750 Holley DP no choke on my 502, both work well.
 
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