New 2x4 carburetors for fe

[v8Dave]

Hello Everyone
I am after some advice and recommendations on who/ where is the best place to get 2 new carburetors for a ford fe 445 stroker also what cfm size would work best? Dual 450cfms? Dual 600cfms?
I have built a 445 fe stroker engine to replace the original 428 pi in a 67 gt500 so the original motor can be shelved/preserved.
Although the stroker motor has trick flow cyclinder heads (painted blue and the name filled in)the motor has been built to look factory stock as best as possible to the untrained eye.
I understand the factory set up uses the 600cfm bk/bj carbs and I could swap them over however i would rather leave the original carbs on the original motor and this is one area where I would rather just get some new more modern carburetors with better tuning abilitys and saftey features with the glass sight windows in the side for checking fuel levels ect. Carburetor colour finish as well doesn't really bother me in this area(factory gold of the 60s holleys vs new aluminium finish on quick fuels for example)
I am running the c7zx-9425-a  medium riser blue thunder 8v intake manifold and also have the dual carb throttle linkage made by blue thunder.
I have done some research and understand about the factory original carbs like the 600cfm bk/bj carbs that have ford specific throttle shafts that work with the factory linkage.
So my question is which brand holley/quick fuels is best to go with and what models? What cfm rating would you recommend dual 450cfms/600cfms.
Is dual 600cfms to much I read an article once I believe in hotrod magazine where they tested dual carbs on a fe and the smaller carbs worked better I believe?
All of you running or building dual carbed fe engines is there someone that you could recommend website/person that could spec me two carbs for my fe that would be all good and ready to go with just normal minor adjusting and tuning so they have the right throttle shafts ect?
Any help and advice you could give me is much appreciated. I have been researching this question for days and I hate to ask dumb questions but this is something I need to get right the first time and could use any information or help given.
Many thanks for your time.
Have a nice day.

[Joe-JDC]

It all comes down to the camshaft you are using as to which carbs work best and how you will be using the car.  I have run two 600s, two 660s, two 750s, and two 860s.  The 600s with vacuum secondaries and balance tube worked well on street, the 750s were quicker, and got worse mileage, the 660s were quicker and got terrible mileage.  The 860s were all out racing.  With the BT dual plane 8V, for street the 450s will be too small IMO, but other opinions are welcome.  Joe-JDC

[thatdarncat]

Personally, for you, I’d recommend getting with Drew at Air-Fuel-Spark. He specializes in both restoring original Ford/Holleys, and building really nice, generally correct looking, common Holleys for Ford 2-4 bbl set-ups. The ones he builds will have the correct throttle shafts for the factory style linkage, and a good calibration for 2-4 bbl usage. Like Joe said, Drew can help pick you a size based on the specs of your particular engine, and how you intend to use it. In my opinion the 450’s are too small, and no, the factory 600’s aren’t too big, you have to remember they are vacuum secondary carbs. Drew builds carbs from his cores periodically and puts them up for sale. Just be aware the carb business isn’t his only career, might take a bit to get what you need, but it would be worth it to save tuning hassles. He has a website & facebook page.

https://www.afscarbs.com/

[e philpott]

I'd call Drew and see what he has available, myself I would opt for his 3310's (dual 780's) that he converts to Ford spec

[Drew Pojedinec]

Man I wish I could build more of those 780s. They are awesome.

2x4 600s are fine for most builds.

[My427stang]

1st - Drew's 600s are easy, beautiful, work great and will feed your engine fine, do it without hesitation.  I have made over 600 HP with his 600s.  I use them regularly and they are an "easy button"  There are some later model 600 carbs that have multiple holes to allow linkage use but in general, they don't look the part and need some tuning to run like Drew's. 

As far as your Hot Rod test, that was Eric English and his buddy that showed that 450s hung in pretty well, and they did.  I believe they were actually vac secondary 465s though and although I have ran 2x 450 tunnel ram carbs on a dual quad with success, I don't recommend it.

Ironically, I built a 457 for Eric English, same guy, many years after the test.  Hyd roller, CnC ported iron CJ heads, TW, nice rowdy pump gas street/strip. We put his 465s on, made 550 HP, put a set of Drews early annular 750s on, 550 HP.   Sounds good but the real difference was torque. Drew's made over 30 ft lb more, not insignificant, but I will say we didn't do any tuning on them either because I borrowed them from Drew and I mistakenly thought I shouldn't go inside.  There was more power there, I wish we would have. 

Can we apply it to your build? I think so, your heads are better, but Eric's intake was better for peaks, so hard to tell how different it would be, especially without cam data, but I go back to the first thing I said.  Easy button.

[Drew Pojedinec]

Wish I had a cheaper way to buy in annular boosters.
I would need a lot of dyno time to dial them in as I never ran my car super hard on public streets.
The 447ci fe runs out of road long before it runs out of throttle.

Not sure on the dyno how they hang, but I can say from extensive wheeltime they really hit hard in the lower ranges.
You can certainly tell a difference.

[frnkeore]

It seems to me that the best way to pick a carb size, is using a vacuum gauge.

If your not down to at least 1.5" at your peak shift rpm, you can use a higher flowing carb. Once you get there, or lower, then carb tuning is what will get your final max HP and TQ.

[cjshaker]

Nowhere is the intended usage mentioned, which is important. Since this is, I assume, an original '67 GT 500, I'm gonna guess that they won't be slamming gears on the strip or tearing up the pavement on roadways. If it's just going to be a cruiser, the 450's would work okay, the 600's would be better for power, and the 780's would be overkill. If you want to have some fun and not limit the engine, the 600's would be a good choice. The 780's would be the better choice if you want max power and/or want to race....but I doubt that's what you're after. I would avoid the 660's for a street car.

FYI, the repro 600's work fine on my car, street and strip. They did take a little bit of tuning to get smooth transitions, but nothing major. They are a compromise of the factory BJ/BK's, basically just standard Holleys set up to work with the factory linkage, so won't be perfect out of the box.

[v8Dave]

Thanks to everybody for taking the time to message and respond to my question and offer me help, its much appreciated.
Doug I'm sorry I forgot to posted how the vehicle is being used. Yes it's a genuine 67 gt500 and will be mostly street driven /cruising with the occasional spirited driving shifting at 6000-6200rpm at the most when doing some spirited driving,but mainly normal driving and cruising.
The car would be lucky if it ever went to the drag strip twice in its life with me anyway.
So I'm guessing twin 600cfms it is and I will have to get in touch with drew at air fuel and spark and speak with him.
The camshaft is a custom hydraulic roller from Brent at lykins motorsports who very kindly helped me out with the camshaft along with a set of morel roller lifters and Brent's roller rockers at 1.76.1 ratio.
Thanks again everyone for your help and suggestions.
Kind regards