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Easiest carb to set up. Holley or refurbished Thermoquad?

Nick Galluscio

Nick Galluscio

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Im looking to replace the carb on my 74 charger. (All stock 360 4 bbl.) which would be easier to setup and get running out of the box: Refurbished (by Summit), or new Holley (which ever Holley is most compatible for my motor). I plenty mechanically inclined, just not in the fine art of carbuerator set up. (Im not a racer or speedster, just cruise around the neighborhood).Any thoughts or experiences would be greatly appreciated. Thanks!
 
Edelbrock carbs are a piece of cake to work with. Basically its the revised AFB Carter carb that was used on a sh!t load of Mopars, great carb for the money IMO.
 
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Nothing wrong with the Edelbrock but it can't compare with a correctly set up Thermoquad.
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62MAX said:
Nothing wrong with the Edelbrock but it can't compare with a correctly set up Thermoquad.
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Nothing wrong with a TQ if you can find one that's not hammered. TQ's plastic main body is the weak link with that carb (Oh Boy wait for it..) and they weep a bit around gasket areas as the gaskets get some time on them. I dropped a Eddy on my Power Wagon a few years ago ( factory 360 CID, 4speed, 4 bbl). Did some minor tuning with the mixture screws and idle speed. Haven't had to touch it since, except to tweak the choke settings for summer/winter driving.
Is the factory carb worn out? or are you just wanting something different?
 
Thermoquad. If you get the correct Thermoquad for your application the factory has done most of the work for you.
 
Send your TQ to Scott Smith at Harms and have them refurbish it. He did one for me and the quality was excellent. Running it daily for the last 5 years on my 88 D 350. The TQ is my vote.
 
A sponsor over on A bodies is Woodruff Carburetor Specialties. Looks like they do fine work too.
 
68Moparmaniac said:
Nothing wrong with a TQ if you can find one that's not hammered.
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That is correct, it took me a few years to find a good one, and now that its dialed in, love it, and when I stomp the gas and get that low growl when the secondary's open, and she takes off like a rocket, it sure makes me smile! I'm actually running one that is specific to a 74 400, but works well on my 340 with higher compression and bigger cam!
 
I love the TQ. As mentioned above, finding a good one and dialing it in not just correctly but with excellence is a OIA & a chore but so worth doing!

I would not go to Summit for a TQ, they just have someone building cores that have been reported to come back with a mixed bag of wrong jets and rods. They also have no control over what exact model your going to get. You may get a small primary, early 340 carb, you may get a large primary 400 snigger from the mate ‘70’s.

As mentioned, DANA of Woodruff carbs and Scott Harms who does exquisite work on these things can probably provide you with the carb you want or you can send them one that you want to run.

My only tip is to get the earliest one possible except the first year of the OE offered TQ. They are air metered unlike the rest of the production line.

Also, get the TQ with the large primary. There best for a 340 and up. Stock or performance.
The smaller primary TQ’s are really good for a enhanced throttle response and mileage that work best in the smaller and more mundane builds. Like mid and late smogged out engines, like a ‘78 360 or 400, or stock to HP 340, 318, 273 engines.

The electric choke version is readily available if you look around and the 1 wire electric choke makes life simple and easy on all fronts.
 
You will NOT beat the performance of a T-quad, particularly if your Charger is an automatic. Your 360 would have come with the big T.- quad, 850 cfm
 
Nick Galluscio said:
Im looking to replace the carb on my 74 charger. (All stock 360 4 bbl.) which would be easier to setup and get running out of the box: Refurbished (by Summit), or new Holley (which ever Holley is most compatible for my motor). I plenty mechanically inclined, just not in the fine art of carbuerator set up. (Im not a racer or speedster, just cruise around the neighborhood).Any thoughts or experiences would be greatly appreciated. Thanks!
Click to expand...
Do you need a Carb or just want to say man look what i got?? Changing just the carb will not make a big difference, having the right size carb does.
I just put a 670 Street Avenger Holley and a Weiand intake on my 69 RoadRunner. works awesome the owner before me had an Edelbrock RPM Performer Manifold and a 550 Edelbrock Carb on it. Edelbrock themselves said not to use that carb on a RPM manifold. Anyway I changed the manifold too because the RPM was too high for a stock air cleaner to close the hood. Too many people put 750 and 850 carbs on a motor that does not need them. The formula is multiply your engine size by the RPM's times efficency and divide by 3456 and that is what minimum size carb you need for a stock HP motor. Efficiency is usually around 90%.
383X5500x.90÷3456= 548. So need at least a 548cfm and Holley agreed 670 was the right carb.
I have an 850 Demon on my 67 383 but that motor is pushing 400 HP with built up guts. And is Race type engine. If your carburetor is ok don't change it. Good luck with your choice Holley works for me and the Demon is a Holley Product.
 
I agree on the TQ,
And agree on using the big one, cuz,I have heard that Carters and Holleys, are not rated the same as to cfm; making the TQs actually smaller than the number Mopar gave them. I cannot speak to the veracity of that.But honestly, it doesn't matter much. If you have a manual trans, it's really hard to beat a DoublePumper.
I ran the bigger TQ on a smogger teen with the only non stock part being TTI headers and dual full-length 3" pipes. She loved it. I ran that engine with a 4-speed, and with a 904 and with a 998, and with 2.76s to 4.30s; AND: the carb required very little tweaking along the way.
I even ran it with the Mopar OD box and a GVod behind that,and a super-tall final drive ratio.
But best of all is the TQ moan. Install a manual-shift or semi-auto VB, upshift into third as fast as she will take take it, then go hammer down for as long as you dare. Enjoy the TQ moan....... over and over and over.
 
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@joemish said;
383X5500x.90÷3456= 548. So need at least a 548cfm and Holley agreed 670 was the right carb.
Click to expand...
I always found the carb calculator to be way off and ridiculous in its outcome. The “At least” is accurate @ best. I always 100 cfm to that calculator answer. I think joemish did right.

As a basic, for a 360, I would use a 600 Edelbrock or Holley (drivers choice!) for a basic use to mild upgraded engine. A 750 for a nicely upgraded engine to a mean street stripper and a 800 or larger carb for a light race car.

The same can be done for the B or RB engine, but, it may be a bit light on CFM. Not a huge deal IMO unless your seriously racing the car. FWIW, Early 440’s did indeed come with 600 CFM AFB carbs in there land yachts.
 
TQ is a spreadbore pattern carb as is your manifold. Fitting a squarebore carb will need adapter - yuk.
 
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