I have a 1975 pymouth duster slant six stock i already have a 4 barrel edelbrock carb and i want to put it on my slant. I know i need a 4 barrel manifold does anyone know were i can get one for cheap or sorta cheap lol. and also what will happen if i put this manifold and carb on a stock motor? do i need to upgrade anything else first?

What size of Edelbrock carb? The only size that will really fit is the 500 AVS I believe with the 600 being the more popular ones. I don't believe you will need to truly upgrade a slant any to slap a four barrel on but I think the loss in fuel economy to gains will not make it worth it. The Super Six set-up which is a two barrel may show more gains.

The manifold you are looking for is the Offenhauser, often sold around here for cheaper. Available at Summit I believe, also at Performance Auto Warehouse is where I purchased mine years ago.

Awesome thanx man. So let me get this straight the 600 edelbrock is too big? and the 2 barrel will yield more horsepower while mantaining the fuel economy? and what about the manifolds that have 2 holes for 2 dual carbs would that be the same as a 4 barrel?

and the carb is a 600

You got some reading to do Lucy! Um... yes personally I would argue the 600 is a little big. I've seen them with more success on a 350 than a slant six. I believe mathematically speaking the 600 will produce more top end horsepower than a 390 let's say, but it will be a horrible engine. The four barrel to me is the way to go as it seems more adjustable and can adapt better to future upgrades. However, just starting out and being budget constrained a Super Six is much more worth your time.
The only multiple carb manifolds I have seen are that of dual one barrel setups also sold by Offy. I personally never liked multiple carbs as they tend to be harder to adjust and tune, but are said to have better fuel delivery i.e. Six Pack.
I'm a Fuel Injection guy, I skipped the four after my Super Six experiment and went for the Electronics side. That being said there will be more expire inced guys chiming in soon

For a stock 225 even the Holley 390 CFM 4bbl is a little large. If you're not going to do any head work or exhaust work the Super Six 2bbl is really about all your engine will need or can use. For a bone stock long block I would do the Super Six intake and carb, 2 1/4" exhaust and recurve the original distributor or use the Super Six distributor.

Before spending a dime how about we take a look at what you want from the car. Most people can say 'faster' easily enough, but how much faster? How fast or quick is it now? Is it still completely stock with the catalytic converter and everything? Does the car have to pass an emissions inspection? Automatic or manual trans? How heavy is the car? What gears in the rear axle? How much do you have to spend?

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Joshua

poorer mileage with a four barrel.
I have come to believe this is a myth. A two barrel is always a compromise between power and economy. A four barrel has a primary system which is dedicated to economy and a secondary system devoted to power. At daily driving throttle openings there is no reason the 4 bbl should give lower mileage. In fact it should be sligtly better if well choosen and set up.
While not an exact comparison ofthis I will give an example. My MAX WEDGE with a holley 850 on a max wedge nascar intake gives almost 15 mpg (IMP) if driven normally like a human being should. By that I mean on the front two barrels. I set this one up specifically that way with a swap for primary jet size reduction offset with PVCR increase. This gives a leaner cruisng mixture but the same fuel delivery under full power when the vacuum drops and power valve is opened. If I drive normal it is a very servicable daily driver and I use it all summer BUT if I put the pedal to the metal I get to do that 8 times (literally)on a full tank of gas than I must find a gas station quickly.Why because the primaries are very efficient and economical in light trottle application and under full power the secondaries and reworked PCVR circuit deliver all the fuel the engine can use . An AFB or AVS can be set up so and in fact the electric choke versions are right from the factory. A two barrel set up would have to be fudged a bit to give suffcient power . The Q jet and thermo quad were extreme examples of efficient primaries and full power secondaries. In fact I would on a street or street strip application be very tempted to try a slant 6 with a sideways mounted Q JET . I suspect it would be a very good set up. It was used by GM on the overhead pontiac Firebird 6 cyl and any of those I have driven worked very well.
Don

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Don

I want to make the car as fast as possible but still be a daily driver. I eventually would like to turbocharge the six. I want to dust eights! lol i believe a fine tuned and done right six is a much more admirable engine than an eight. i love eights ive had 2 monte carlos 305s with performer packages. thats were im got the edelbrock 600 from. but yea ive got a 1975 plymouth duster completely stock only upgrade so far is a flex fan. I want to do it right and make it fast. i probably will need to pass emissions and not sure the gear ratio i know its a one legger. with that said should i try to put the edelbrock 600 on or get a smaller 4 barrel? If not a 4 then should i get a 2 barrel carb and manifold and how much of an hp gain will I see with the 4 barrel compared to the 2. Also when putting on a bigger carb do i need to change anything else on the engine before hand

If you have to pass emissions with the car you'll be limited with what you can get away with. If there is a visual inspection you're extremely limited.

If you have to pass emissions, but don't have a visual inspection you'll need to stay with a conservative cam and/or spend a lot of money and a huge amount of time with EFI.

The 600 Edelbrock is too big. The Super Six 2bbl package will be an improvement, but you won't dust any decent running V8 in a similar vehicle.

If you have an automatic trans you'll need to retain the throttle pressure linkage which ends up being a project as time consuming as the manifold and carb swap.

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Joshua

okay im guessing the super six is the best way to go so ill be attempting that but now what about the cam what cam does anyone suggest? and what header should be used? and with all these improvements what will i be looking at in terms of horsepower?

Well, I would estimate minimal. To start with I would say that the headers available would be very costly for the gains you might get. The money would be better off spent towards head work or something else. I would first suggest that you read the Matrix Thread and this current topic going on:
http://www.slantsix.org/forum/viewtopic.php?t=37214

I'm concerned that you want to apply V8 techniques or bolt-ons to see big gains. That isn't really how the slant works, not to say they aren't all engines but there is a couple differences, for example I will use my favorite the 340. The 340 was already a great engine with compression (something the slant lacks), and good flowing heads. The heads on a slant were designed for a 170 size engine hence why it is so uncommon to see guys port out to a cfm per a cubic inch for the 225. However, a smaller cross section will also mean slower velocity which is a benefit to the torque monger that is the slant six. So all in all and 340 would respond well to a purple shaft, headers, and a large carb. This simply won't due as well for the slant, I have found that for an initial investment it was far more worth my time and money to put something like a Super Six and an RV cam with better gears than to waste my time trying to get expensive parts (since headers are so common ). So maybe rethink some goals and work through one of the two scenarios listed above. I think it would be doable to see 185hp with mine with little money, and 250 with the thread being discussed above. However, the torque numbers would be much much more impressive which is what you will have to measure with the slant anyways.

Im getting the feeling i should sell my edelbrock 600 lol

i am running an edelbrock 600 ....i have run thermoquads,quadajet,and holley 650 vac sec...on both stock and built slants....alway gained power and milage


keep on roddin'

Thats awesome man i wanna put my 600 on sooooo bad. I hope im doin the right thing!

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Racing in a honda is like the special olympics...
even if you win your still retarted.

How much of an increase in hp did u get with the 600?

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Racing in a honda is like the special olympics...
even if you win your still retarted.