New Intake & Carb on 383 ?

[VANDAN]

I'm looking for some input on my '70 Dodge. The engine is a '71 Factory 383 Warranty motor, basically 335hp, 4-spd, with a mild cam, and aftermarket rockers, running stock HP Exhaust Manifolds, nothing radical. A friend gave me an Edelbrock 7186 RPM Intake, along with a Holley 670 Street Avenger Carb, H80670. I was thinking of putting the set up on, and modifying a Mopar Oval Air Cleaner (6-Pac style), to let it breath easier. Any thoughts as to whether the 670 is a good size for this ? Currently being fed with a 5/16" fuel line, and the carb is a dual pumper, 3/8" feed. Any & all input appreciated, Thanks...

 

[65-440]

I'm running the 770 street avenger and an eddy rpm manifold on my warmed up 383 .... I like it, I think you'll be fine with the 670

 

[vintage chromoly]

While that gear will work on the 383, I don't think you'll see any significant advantage to it.
I'd leave it be

 

[Don Frelier]

Sure looks nice the way it is. I'm still not sure what carb you have today? Holley 650 double pumper?
You might want to try the intake first. Then maybe the carb second.
I ran a Carter AFB 625 for years on mine with a similar engine and I don't think it was
"carb limited". I can tell you that cool air will really help. I run a Ram Airbox with hoses to the core support for cooler air.

 

[Bee1971]

Switch over from a Factory Carter AVS 625cfm found on the 383 HP

To a Factory Carter AVS 750cfm found on the 440 HP

And let me know what you think

You won't bee reinstalling the 625cfm carb anytime soon
Of course , based on both carbs in good running condition

And the RPM Intake is a huge improvement over the factory intake

But hood clearance is always an issue

 

[PurpleBeeper]

I really like bee's suggestion to stay with a Carter carb, just a bigger one since you won't have to modify that beautiful air cleaner. I don't believe that using one of the big oval air cleaners will help you much, if at all, unless you go all out & add the whole ramcharger setup.

I was surprised to see some stock 440 horsepower tests with various aluminum intakes. It was on this site 1-2 weeks ago, so search for it since you should see similar results on a 383.

Hood clearance is DEFINITELY something to consider. If you go with a really tall intake, you may have to use a racing-style "drop base" air cleaner.

I suggest you measure how much hood/air cleaner clearance you have (big wad of clay?) to play with. Compare the intake heights from the 440 test(s) on this site & pick the best performing "not-so-tall" dual plane one.

If you have any room left, maybe put in a K&N air filter that's just slightly taller than stock, so the lid of your air cleaner is up off the base maybe 1/2"-1" to get more air flow. I highly recommend this and just suggested it to my best friend yesterday for his Nova.

You may have to make/modify a K&N filter to fit. FYI- the other similar brands that you oil are just as good in my opinion. I know K&N didn't make one for the '70 4bbl. air grabber air cleaner when I looked 3 yrs. ago.

Whoops! I saw what you got for free....sure, try the intake, but don't swap the carb since you'd have to modify/cut some air cleaner. Most Mopar bases I've seen are made for Carters.....though some 440's had small Holleys. Maybe you can find a base that fits & keep your lid so you can use the 670?

 

[65-440]

My 70 340 uses factory air cleaner and base, my 68 383 also ... both fit just fine on Holley carbs ....

 

[Jcharger]

The 670 will work fine, but you will probably need to run larger jets than the ootb set up, and then after that look at the pump circuit.

Can you give more information on the carb on it now? Is it an AFB? Sorry to ask if it is obvious.

You will likely need a drop base air cleaner with the RPM intake. Be careful closing the hood when it is first installed. You may also need a throttle adapter plate to make sure the blades open all the way. You will also need another cable holder/adapter.

 

[LemonWedge]

Looking at your car, I see this as a slippery slope. No doubt it’ll breath a little better up top, a 770 would be even better, but there’s the slippery slope. Today it’s an intake and carb. Next it’ll be a set of headers. Then more cam. Pretty soon a converter finds its way into the conversation..... and away you go.

The engine compartment looks like a stock resto type deal, and a really nice one at that. Think long & hard about what You want the car to be, because the hotrod bug tends to bite deep.

 

[wyrmrider]

good advice on the 440 carb or an AVS
I'd save the Holly for a stick shift

 

[65-440]

That Holley is vac secondary, does not need to be for stick only .. it'll run just fine

 

[BSB67]

I'm running the 770 street avenger and an eddy rpm manifold on my warmed up 383 .... I like it, I think you'll be fine with the 670

I generally agree with this.

At the risk of being Negative Nancy, but here goes:
I suspect that we might not really know what's in the motor. Is it really an untouched 383 from 1970? If it is, its probably wore out, if its not, the compression ratio is probably much lower than the factory rating due to poor piston choices. Same with the cylinder heads. What do you know about them for sure. If original, the're wore out too, if rebuilt, they are probably still marginal at best because almost no one will spend the necessary $ to bring them back. Add sunk valves and a fat head gasket (typically used) and you end up with a 383 weakling and no carb and intake will really help much. I could mistaken, but I have seen this exact scenario a lot.

A good solid 383 short block and good heads will like a 750 cfm carb, and the standard Performer will all it will need at you potential power level, and you won't have hood clearance issues.

Do a cylinder pressure test. That will be helpful information to see where you are at.

 

[65-440]

I generally agree with this.

At the risk of being Negative Nancy, but here goes:
I suspect that we might not really know what's in the motor. Is it really an untouched 383 from 1970? If it is, its probably wore out, if its not, the compression ratio is probably much lower than the factory rating due to poor piston choices. Same with the cylinder heads. What do you know about them for sure. If original, the're wore out too, if rebuilt, they are probably still marginal at best because almost no one will spend the necessary $ to bring them back. Add sunk valves and a fat head gasket (typically used) and you end up with a 383 weakling and no carb and intake will really help much. I could mistaken, but I have seen this exact scenario a lot.

A good solid 383 short block and good heads will like a 750 cfm carb, and the standard Performer will all it will need at you potential power level, and you won't have hood clearance issues.

Do a cylinder pressure test. That will be helpful information to see where you are at.

Your negative nancyness is very valid ! Condition of the engine in question is very important ... my comments are only based off my experience with my fresh built 9.44:1 aluminum head 383, the 770 and RPM manifold work well !

 

[VANDAN]

I am running a Carter 625 on the car now, with a stock intake manifold. The car runs decent, but does tend to get some vapor lock when it's warm out, and been running for some time. I'm sure that comes from the limited, hot air intake with the stock pieces in place. I know everyone would pull the heat stove & flex tube off first thing to stop the excessive hot air build up at that point. It will get up to 130+ on a local expressway no problem, and runs smooth with more in it, so the motor's not too ragged out at this point. I was just looking to change it up a bit, seeing as I have the parts around. I also have an Edlebrock 1407 sitting on a shelf, which I could also try out. Not looking to go to headers, or make a strip car out of it either, but may swap the 3:23's out for a 3:55 - 3:91 set, just to add some punch to it. Thanks to ALL for throwing in on this, and it is up in the low 60's today, so Spring is on the way...

 

[65-440]

Best thing you can do is use the felpro 1214 intake gasket that blocks the heat going to the intake, that will help your vapor lock tremendously ...

 

[wyrmrider]

use your old small fuel line as a return and run a new larger fuel line with one of those neat fuel filters that have a vapor return built in
just going to a fuel line from an HP car makes a big difference if your car was non hp in the first place 1/2 is better (calculate the in/ sq) and count the bends
insulate your fuel line
blocking exhaust heat depends on weather in your area as does exhaust stove on the exhaust to the air intake
there is a reason the factory spends all that money on these things