Hey guys what do you think about an eddy ch28 2x4 intake with 2 600cfm eddy carbs on a 4.15crank 440 with cnc ported stealth heads 580/250@50 cam,.or a single plane weaned 7512 with a 950holley?has to fit under stock hood for a 70 runner.

In my limited dyno testing on a 500 inch motor with similar cam size (248 @ 0.050, 0.605"), the Holley SD with a small venturi 950 made considerably more peak power and more average power than the six pack. I think most folks state or claim the six pack is as good or better than the Eddy 2x4. I don't know if that is true, or how the Weiand compares to the SD.

With that, my guess is if the goal is just max power between those two, probably the Weiand/950, but that is a lot of extrapolating to come to that conclusion. I'm not sure any of this helps.

FWIW, the 440 2D and the SD were similar in power overall. The SD had a few more hp up top, but the 2D had a little more in the lower rpm resulting in about the same average power. The 2D will fit under the hood.

thx BS.... I'm taking the six pack off and going either one of those 2 setups.

On my 499 wedge, I tried several different carbs. The Dominator won and drove as good as the 950 after Dominic (ThumperDart) got done with it. My favorite intake was the Holley SD modified to take the Dominator. It was an easy mod that I did myself. And it fit under the hood, too.

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So you modified a Holley Street Dominator with the 4150 flange to accept a Dominator carb?! 🤔

Yep, it is fairly simple.

I got 4 aluminum bolts, screwed them in till tight, and cut them flush. Used a 4500 gasket for a template and drilled and taped the 4 new holes and opened the plenum up. Not a big deal at all and worked just fine.

Is there a penalty in TQ or HP using the SD vs. Eddy Perf RPM intake on a street application?
The RPM can be a tight fit for stock air cleaners clearing the hood on some cars, and sometimes a dropped base can't be employed.
I would assume the RPM would make more power, but a stealthy street motor's gonna spend more time in the 1500-3500 RPM range.

A little loss in lowend, but not very noticeable. Years ago I did a same day track test b/t the two manifolds on my old 440 that ran 11.40s at 117 mph in my cuda. The ET and MPH were almost identical, but the 60 foot was only .01-.02 slower w/ the Holley SD. On the street I really couldn't tell a difference. The car had 4.10s and a 3500 stall FWIW.

wow you guys really love the Holley SD.....ive seen em around and think you can still get em I just don't like the look of them.

I'm a big fan! It keeps everything under my stock, flat hood even with a nitrous plate and phenolic spacer.

The Holley SD is very ugly but it seems to work okay. The dual carb Edelbrock manifold has a nice look to it and it works really well with the correct Edelbrock duals. I've run that combo before and it is nice for a street driver.

Dual quad Edelbrock set up may not make the most peak power but it looks perfect on a 440. Plus it does work very well!

I believe the answer is yes for down low power, but not up top, but I also think the how much will depending on the engine specifics.

I think when you cross the 450-500 hp threshold the SD will start making more peak hp. The higher the hp application the difference will become greater. Regarding "penalty in TQ" I'm not sure exactly how to respond. I'll assume you me down low power, or a lower rpm TQ peak. In the dyno testing I was actually surprised how much the SD gave up below below 4000 rpm on a 508 cuin engine. It was not huge, but I guess I was expecting something closer to zero difference between the SD and dual planes tested, which were nearly identical below 4000. Then you need to ask if giving up a little low end on a 500 inch motor matters.

My buddy runs the Eddy 2x4 intake with 2 600 Eddy's in his 65 Belvedere (all stock body street car). 440+.030",10.0-1, .557 Mopar solid, unported Eddy RPMs, cheap headers, decent converter, 4.10 on 93 pump gas. Will run 11.30-11.40 anywhere. Been 11.28 best.
Doug

I'm not sure I understand the concern over 'low end' torque. With a lot of cubic inches, I have not had any converter that wouldn't flash well above 3,500. In fact, my biggest issue has been getting a converter that doesn't feel mushy down low. And even you stick guys, do you really feel a need for a little more torque way down low? Now understand that I don't think that there is ever too much torque, but here we are talking about the difference that intakes make way down low.

A mute point in my experience.

I suppose it matters to the people that put 2.76 to 3.23 gears in a muscle car that came with 4.10s because they think it should be able to cruise 75 mph at 1500 rpm like a modern car that has Variable Valve Timing, Variable Length Intake Manifold, 2 overdrives and a lockup converter. I'm not one of those people. I like 4.10 gears. They work the same now as they worked in 1970. 3500 rpm on the highway for short distances won't hurt a thing.

An intake that works at 1500 rpm will not help if your cam doesn't get happy until 3000. Try to match your cam, intake and gears to the rpm range you want to spend time in.

i use a ch28 on one of my 440's with two 600 edelbrocks. absolutely without any doubt in my mind the most street friendly reliable intake system i've ever run. i'd use 750's on a big engine or at least two 650avs2's.

thx guys I'm gonna try the CH28 2x4 with a pair of 600 eddy carbs.....its been mid 11s with the stock 6bbl 3.55s and stock vert.

I agree. For whatever reason it seems to be what many prefer.


I attribute it to a difference in driving style.

^^^ Because I already have a race car, but was curious about the SD intake on a 500" BB on the street.
Last 512 had an Indy top end & single-plane and required a hood scoop to clear
The difference in manifold height (RPM vs SD) may be a problem for what I have in mind next time.
Which isn't going to be 6000RPM clutch drops at every traffic signal.
But an occasional 2000RPM surprise leave could happen...

Great. Post your driving impressions and track results. It will be good to get real comparison data.

the 600's are the same size venturi and throttle bore size that street hemi's, early s/s wedges and IIRC the old 409's had; definitely not on the large side. keep in mind that chrysler offered a larger set of carbs for the '67 hemi's (which were identical in throttle bore and venturi size as '67 440-375hp and '64 wedge s/s and 750 edelbrock) because the original carbs really weren't big enough. add another 75 cubes and the idea of larger carbs is more enticing. don't let cfm ratings and all that muck control your choices. the 650avs2 has a little larger secondary than the 600 plus an adjustable air valve. i also like the annular booster. i've been up/down/sideways and every direction you can go with my carbs and the truth is they're close to being the way they were as they came out of the box. i've always wanted to try a pair of 750's (they don't really do 750cfm) but been too cheap to buy a new set of carbs. i do believe my engine wouldn't have any issue with 750's. as far as WOT throttle goes my carbs are very smooth. no hesitations, hiccups, bogs, nothing; just smooth power. i run a progressive linkage like the street hemi's which is good for driving but not the greatest for trying to pedal the throttle in low gear. this set-up will flat blow-off the 275-60 tires i have on the back at will in low gear from any speed. very good mid-range power; even with a 3.23 gear. i can lug the car down to 15mph in high gear and just give it some throttle and it cleanly drives away. these quads are also the cleanest burning fuel system i've had. i used to be a die hard 6pak guy but this set-up has really changed my perspective. i like 6paks for shear power in a street engine but considering a ch28 set-up is half the price with fewer headaches the choice gets simpler. i'm not a fan of big holley type 4bbls and single plane intakes for street driving. they don't necessarily make power because the single carb is so wonderful but because the intake manifold flows more air; sometimes a lot more air than a dual plane. but, large venturi and throttle bores don't always mix air and fuel good at low rpms and for what i do i don't want to give up torque below 3500rpm.

That setup looks perfect on the mopar440. In my opinion because of the mopars wide intake manifold I think dual under hood quads looks better on the 440 than the 454 and all other makes. Plus it pays homage to the days of more power mandating more carburetors.

i wanted to keep the '60's theme with the car. it's not over gadgetized with modern stuff.

i have always wanted to try a ch28 with two 1 3/8" bore primary thermoquads. [800cfm ?]
i know i would have to fab some offset adapters because the ones available would [i think] not allow the carbs to bolt on because they would hit each other.

Offenhauser also still makes an under hood dual carb intake for the 440 with more carb spacing than the Edelbrock. But I have read the single plane Offenhauser is not as great a performer as the dual plane Edelbrock.

Your correct on that
Been there, done that
The early Fire Power Hemi and inline dual quad wedge Mopar OEM motors came with single plane dual quad manifolds with progressive linkage, they flat suck compare to the stock 426 street Hemi motors with the dual plane intakes

I already have access to the eddy intake and carbs so its even more simple.....now what about an air grabber breather setup for 2x4?I believe spacing on the hemi is different correct?

hemi carbs are further apart. you'll probably to get a little creative. it may be possible to take the edelbrock air cleaner base and adapt it to a factory base. the manifold height for the ch28 is noticeably taller than a stock iron 4bbl, and i think about 1/2" taller than a ch4b but shorter than a ch6 or RPM intake.

thx lew

i forgot about the CH28 being taller than the CH4B. i already have a drop base air cleaner [moroso] on the T-Quad with the 5/8" thick adapter needed for the CH4B, and the stock hood on my charger barely shuts now. i guess the CH28 is out of the question to use.
i don't want to cut my hood for a scoop, so unless i can find a taller flat hood, i'm out of luck.

Have you considered lowering the K member?

not cutting anything up on my '65's body was a prime objective. i have at least 1/2" of clearance between the hood and air cleaner wing nuts. my engine is in the stock location. the edelbrock alum air cleaner is a no go; way too tall.

Lew any pix of your engine air cleaner setup?

this is what i'm currently using. adequate for the majority of my driving; small for racing.

that never crossed my mind. how much would be the max ? 1/2-3/4" ?

I learned a long time ago that every time I made the B and RB motors consume more air and fuel, improved that, they all made more power at the track drag racing Same thing on the street also
Go big or leave power on the table
If your going to run 2x4 on progressive linkage look at using a set of 750 or 800 CFM carbs

my engine is 445". no big cam, compression, or professional done heads. no low gears or loose converter. but, i do believe it could handle 750's without a hiccup, and make a little more power.

That is the range. I usually go as much as the steering column or radiator shroud will let me. If it were possible to mount your carb without the adapter (or mill the intake down that same amount), combined with the 'K' drop, it would give you over an inch of extra clearance to the hood.

I have an Indy intake and Dominator carb under the Shaker on my Cuda. Dropping the 'K', lowering the radiator, using a drop base air cleaner base, and modifying the air cleaner lid was the combo that made it possible. And you cannot tell it by looking at it.

Ive ran some smaller intakes on my 512. Streeter. It still ran like a bear. I went 10.95 with a ported six pack and 10.92 with a TM6 and a 4150/1050. I have a Indy single and a dominator on it currently and it feels stronger but, it’s gonna get the six pack when I put a 4 speed back in. The TM6 is surely one of my favorites for street duty.

Not having to use the 5/8 thermoquad adapter won't help enough?

not using the adapter WOULD help, but i would like to try a pair of T-quad carbs without hacking on the intake, plus use an air cleaner of some sorts other than a pair of tiny diameter ones that have only 1 1/2" thick elements.
the other option would be to use my '62 max wedge intake with it's small factory [3407 ?] carbs.
once again, height may come into play, as i would like a good air cleaner without hacking up my flat hood.

A pair of Plastic Fantastics ? ... I didn’t know the from Coder was a wanna beez member of the ThermoSquad !

I had a DUAL QUAD intake for a pair of TQs .....

But it was way WAY YESTERtech !

Kinda like most of the from Puttsylvania

pretty sure you would need to cut the under hood bracing out to fit a cross ram with air cleaners. the plenum under the carbs of a ch28 isn't large and would take some work to get those 2 1/4" throttle bores in there. 1 11/16" throttle bores are pretty much the limit on my intake.