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...