Still need some heavy schooling on carburetors

[SRKlegin]

Good morning,
I can't believe that I am stumbling so bad on carburetor selection. During these last 3-years I have learned a lot from you guys, but I have heard so many different suggestions for the right carb and my budget can't handle a mistake so here's what I have:

Engine: 1973 340LA / stock pistons (new) /crank (steel)
Stock Cast Iron Heads: 3671587.9 / 3671587.8 / 2.02 and 1.88
Valve Train: Retro-Fit Roller Lifter and Ultra Pro Shaft Mount Roller Rocker arms
Intake: Stock 4BBL Intake: Part Number:
CAM: Xtreme Energy Retro-Fit XR268HR-10 Hydraulic Roller Camshaft
Lift .531"/.531"
Duration 268/276
Lobe Separation Angle: 110°
RPM Range 1400-5500
Transmission: A904 3-Speed Auto / Rebuilt / TF-2 Shift Kit
Rear End: 8 3/4-3:23 ratio
Tires 17x8 and 17x9

I have a throttle cable that is installed for the original 318/2BBL
-- This will work for a 4-BBl set-up, correct?
So in essence, I would like to use my original 340 stock air cleaner and it's imperative that I find the right carb to handle what I have. I am sorry for being ignorant, but I just want to do this once.

 

[SRKlegin]

Good morning,
I can't believe that I am stumbling so bad on carburetor selection. During these last 3-years I have learned a lot from you guys, but I have heard so many different suggestions for the right carb and my budget can't handle a mistake so here's what I have:

Engine: 1973 340LA / stock pistons (new) /crank (steel)
Stock Cast Iron Heads: 3671587.9 / 3671587.8 / 2.02 and 1.88
Valve Train: Retro-Fit Roller Lifter and Ultra Pro Shaft Mount Roller Rocker arms
Intake: Stock 4BBL Intake: Part Number:
CAM: Xtreme Energy Retro-Fit XR268HR-10 Hydraulic Roller Camshaft
Lift .531"/.531"
Duration 268/276
Lobe Separation Angle: 110°
RPM Range 1400-5500
Transmission: A904 3-Speed Auto / Rebuilt / TF-2 Shift Kit
Rear End: 8 3/4-3:23 ratio
Tires 17x8 and 17x9

I have a throttle cable that is installed for the original 318/2BBL
-- This will work for a 4-BBl set-up, correct?
So in essence, I would like to use my original 340 stock air cleaner and it's imperative that I find the right carb to handle what I have. I am sorry for being ignorant, but I just want to do this once.

 

[SRKlegin]

Here's my intake I plan on installing on the 73' 340LA

 

[Xcudame]

I just posted this book on another post. You would love the information in it regarding Carter carburators. And I'd find a good used 72-74 Thermoquad, rebuild it and run it. I was also posted a link to Vaanth's post about Thermoquads. Wealth of info.

https://www.amazon.com/Super-Tuning-Modifying-Carter-Carburetors/dp/0931472113

The Vaanth Thermo-Quad Guide, re-written and updated.

Hello FEBO, I recently joined and introduced myself in the Welcome Wagon forum. Some of you may have seen my user name, Vaanth, before. I have used it on several things and several places since I coined it in 1979. In 1998, I wrote a document called "A Carter Thermo-Quad Guide" while on the...

www.forebodiesonly.com

 

[EV2RTSE]

I have a 73 340 car, when the big secondaries kick in on the Thermoquad it's awesome. So yeah I'd also suggest either an original TQ or if not I'd look into the Street Demon, it's basically a modern version of the TQ.

Read this-
https://www.hotrod.com/how-to/street-demon-750-carb-review/

 

[SRKlegin]

I have a 73 340 car, when the big secondaries kick in on the Thermoquad it's awesome. So yeah I'd also suggest either an original TQ or if not I'd look into the Street Demon, it's basically a modern version of the TQ.

Read this-
https://www.hotrod.com/how-to/street-demon-750-carb-review/

I will look into the street demon. I want to use the stock air cleaner. Love it. Street Demon will accommodate the vacuum lines, etc...?

 

[SRKlegin]

I will look into the street demon. I want to use the stock air cleaner. Love it. Street Demon will accommodate the vacuum lines, etc...?

what cfm?

 

[EV2RTSE]

The stock TQs flowed around 800cfm which sounds like overkill for a small block and yet that's what they used. I'd suggest 750cfm as per the Hot Rod article. I think the phenolic body is a good idea as it helps keep the fuel colder, which is important with today's crappy gas.

Read through this, and if any questions perhaps contact Holley directly and talk to someone.
https://www.holley.com/products/fuel_systems/carburetors/street/parts/1904

 

[SRKlegin]

I have a 73 340 car, when the big secondaries kick in on the Thermoquad it's awesome. So yeah I'd also suggest either an original TQ or if not I'd look into the Street Demon, it's basically a modern version of the TQ.

Read this-
https://www.hotrod.com/how-to/street-demon-750-carb-review/

Will a Holley Remanufactured Carburetor 750 CFM Manual Choke #3310 too much for 340LA engine? Found a refurbished one on EBay for 299.00

 

[mrmopar340]

The stock TQs flowed around 800cfm which sounds like overkill for a small block and yet that's what they used. I'd suggest 750cfm as per the Hot Rod article. I think the phenolic body is a good idea as it helps keep the fuel colder, which is important with today's crappy gas.

Read through this, and if any questions perhaps contact Holley directly and talk to someone.
https://www.holley.com/products/fuel_systems/carburetors/street/parts/1904

795 cfm I think on the 340's.

 

[Xcudame]

Any Thermoquad from 72 to 74 with good butterfly shafts is a good candidate. 800 CFM or 850 CFM. Holley's leak too much for my taste.

 

[moparlee]

Any Thermoquad from 72 to 74 with good butterfly shafts is a good candidate. 800 CFM or 850 CFM. Holley's leak too much for my taste.

Is a 71 TQ different from the 72 to 74 ones?

 

[Xcudame]

Yes. The 71 was only on the 340 and it was air metered instead of fuel metered. If my memory is correct, a lot of the 71 340 Thermoquads got replaced with 72 models as there were issues with the air metered 71s.

 

[Ricks72Chlgr440]

Yes. The 71 was only on the 340 and it was air metered instead of fuel metered. If my memory is correct, a lot of the 71 340 Thermoquads got replaced with 72 models as there were issues with the air metered 71s.

Yes. The TQ strip kits we used to use explicitly said "for 72 and up solid fuel thermoquads".

 

[SRKlegin]

4 Barrel Carburetor for AVS2 Series 650 CFM Electric Choke Edelbrock 1906. Good price on e-bay...good fit for my engine set-up?

 

[SRKlegin]

Any Thermoquad from 72 to 74 with good butterfly shafts is a good candidate. 800 CFM or 850 CFM. Holley's leak too much for my taste.

Man...some people are fighting back saying 600-650 cfm for just cruising. See what I mean? This can be very frustrating, ya know?

 

[SRKlegin]

Man...some people are fighting back saying 600-650 cfm for just cruising. See what I mean? This can be very frustrating, ya know?

My engine didn't come with a carb. wondering if anyone would have a good candidate to send in for refurb.

 

[SRKlegin]

My engine didn't come with a carb. wondering if anyone would have a good candidate to send in for refurb.

for a TQ. It's either that or an AVS. I have a headache. LOL

 

[EV2RTSE]

The AVS2 will likely be a decent choice and for cruising around it should offer good driveability. You might be leaving a little HP on the table with a 650? Call Edelbrock and ask them. 1-800-999-0853

Tony's Parts shows a 73 340 TQ core for $145, that's actually a decent price these days IMO.
Carburetors | Tony's Parts

 

[Ricks72Chlgr440]

The AVS2 650 would be a good choice. Annular boosters provide excellent response.