Which intake manifold

Mojoe9955

Well-Known Member
Joined
May 14, 2021
Messages
239
Reaction score
126
Location
NJ
I'm not sure what I'm looking for, but I want to up the performance of my Slant Six. I'm not sure what is entailed but I assume it involves intakes and headers. Which of these intakes is a good choice? I have a Holley 4412 carb and the 2 barrel intake.
Thanks

20221111_132131.jpg


20221111_132537.jpg
 

Charrlie_S

Well-Known Member
Joined
Oct 17, 2005
Messages
3,920
Reaction score
1,840
Location
Silver Springs, FL
How do you plan on using the car? Any other mods? Stick or auto? Rear gear? Etc? The 4412 is kind of big for street diving on a close to stock engine. The barrels are large, and don't have much air velocity at low RPM, so drivability suffers. For a almost stock engine use the Mopar 2bbl manifold, and a smaller 2bbl carb. That manifold did have some issues with porous welds, but if you paint it with epoxy paint, that will cure any possible problems.
 

HankRearden

Well-Known Member
Joined
Sep 11, 2017
Messages
348
Reaction score
600
Location
PA
I may be in the minority but if it is otherwise stock I would go with the 2v intake.
 

RustyRatRod

I was born on a Monday. Not last Monday.
FABO Gold Member
Joined
Jun 7, 2010
Messages
93,618
Reaction score
82,303
Location
Georgia
I agree with the two barrel intake. I also agree with Charlie that the 4412 is too big. That's 500 cfm. I have a 450 quick fuel four barrel on mine and I consider it pretty heavily modified. Over 10:1 compression, .465 lift 250 @ .050 duration on a 108 LSA. I think the 4412 would be too big for an engine that was much milder than that. I would look at the 318 Carter BBD two barrel. It would probably be much better suited. Maybe even the stock Super Six carburetor if it's going to be really mild.
 

Mojoe9955

Well-Known Member
Joined
May 14, 2021
Messages
239
Reaction score
126
Location
NJ
The car came with a mainfold like that and the carb. It's seems like it's just a stock 225. It actually runs pretty good like it is, it doesn't seem like it gets good mileage though.
 

RustyRatRod

I was born on a Monday. Not last Monday.
FABO Gold Member
Joined
Jun 7, 2010
Messages
93,618
Reaction score
82,303
Location
Georgia
The car came with a mainfold like that and the carb. It's seems like it's just a stock 225. It actually runs pretty good like it is, it doesn't seem like it gets good mileage though.
It would run better with a different carburetor I do believe.
 

junkyardhero

Well-Known Member
Joined
Jan 23, 2005
Messages
302
Reaction score
391
I just did a 1bb to a super 6 2bbl with a BBD. great upgrade on an otherwise stock motor.

like RRR said, for 4bbl you're gonna need a cam and compression.
 

Mojoe9955

Well-Known Member
Joined
May 14, 2021
Messages
239
Reaction score
126
Location
NJ
So the nasty, looking 2 barrel is actually a late model aluminum Super Six intake?
 

RustyRatRod

I was born on a Monday. Not last Monday.
FABO Gold Member
Joined
Jun 7, 2010
Messages
93,618
Reaction score
82,303
Location
Georgia
So the nasty, looking 2 barrel is actually a late model aluminum Super Six intake?
Late model? 76 I think was the first year for the Super Six. Almost 50 years ago? Late model? LOL
 

HankRearden

Well-Known Member
Joined
Sep 11, 2017
Messages
348
Reaction score
600
Location
PA
Back in the way back machine, Holley had a small spreadbore 4 barrel. They called it the economaster. It was like 450 cfm. Something like that may work well on the 4 barrel intake. But slants are such pigs stock I cant imagine anything larger working well.
 

RustyRatRod

I was born on a Monday. Not last Monday.
FABO Gold Member
Joined
Jun 7, 2010
Messages
93,618
Reaction score
82,303
Location
Georgia
Back in the way back machine, Holley had a small spreadbore 4 barrel. They called it the economaster. It was like 450 cfm. Something like that may work well on the 4 barrel intake. But slants are such pigs stock I cant imagine anything larger working well.
I have one. lol
 

junkyardhero

Well-Known Member
Joined
Jan 23, 2005
Messages
302
Reaction score
391
They probably work really well. Although they are a spread bore, they ain't spread "very far". lol It'd be good on a slant 6.
they surprisingly do!

I had a rolling test lab 69 cuda for quite some time and I'd screw around with different intake and carb combos on the tired *** stock 318-2 that was in it.

the 6904MB is a 450 and has mechanical secondaries which played nice with a old school performer. nice throttle response and drivability.

like you I have one holding down the shop floor too...
 

junkyardhero

Well-Known Member
Joined
Jan 23, 2005
Messages
302
Reaction score
391
btw, if you get the super six set intake a BBD out of pretty much anything will bolt up to it. you'll want to replace the mounting studs if you're running the thicker 3/8" (I think) spacer/gasket, but be mindful of the length so they don't foul on the carb body. you'll have to modify the choke or swap it to electric.

also, you'll want the throttle linkage and kick down-- hopefully they have it. not a deal breaker, just makes it a little more fiddly to install.

if they weren't much I'd consider picking up both
 

BillGrissom

Well-Known Member
Joined
May 10, 2009
Messages
7,883
Reaction score
856
Location
Sacramento
There were 370 cfm 4 bbl carburetors, but hard to find today and pricier than a more common 500+ cfm one. In theory, a small 4 bbl carburetor could give better drivability and mileage than a 2 bbl, since at lower power (steady highway driving) you run off just the primary bores which can be smaller than in a 2 bbl. True, the Holley Economaster line might be a good choice. Those were sold aftermarket starting in the late 1970's gas-crisis and generally were smaller cfm than the OE carburetor for the same application. I think they even made a 1 bbl version. You occasionally see them on ebay. If you choose to use the Clifford 4 bbl, I think you need a few other special parts, like a kickdown system which Edelbrock sold (google). While at it, Edelbrock also sold an aluminum valve cover for the slant which is slick, especially if painted a wild color.
 

Charrlie_S

Well-Known Member
Joined
Oct 17, 2005
Messages
3,920
Reaction score
1,840
Location
Silver Springs, FL
I think they even made a 1 bbl version. You occasionally see them on ebay. If you choose to use the Clifford 4 bbl, I think you need a few other special parts, like a kickdown system which Edelbrock sold (google). While at it, Edelbrock also sold an aluminum valve cover for the slant which is slick, especially if painted a wild color.
I have a 1bbl economiser on my 64 Valiant. It did help fuel mileage slightly, but limited RPM a lot. As for the clifford intake, be aware that the stock exhaust manifold will not work.
 

Mojoe9955

Well-Known Member
Joined
May 14, 2021
Messages
239
Reaction score
126
Location
NJ
I'm not sure what I actually have on the car now intake wise, but talking here I think it is a cast iron Super Six. It is missing the stock linkage and I think I read that it needs a shorter throttle cable. It also has some sort of Loco kick down cable and adapter. Seeing that it all works as is and the Clifford needs many more pieces to come up with, I think I'll save the money now and try and find a smaller carb.
Thanks
 

/sixchall

Well-Known Member
Joined
Jan 19, 2017
Messages
295
Reaction score
158
Location
Riverside ca.
when I was driving my Slant6 70 Challenger as a daily driver. I too wanted to step up the performance value of the Dodge. Since the engine was a 1977 p-nut plug replacement engine for the original. I decided to go the route of a cast iron Super Six manifold with a BBD 2bbl off a 318. I had a choice of an aluminum 2 bbl and an Offenhauser 4 bbl intake but I chose the cast iron factory intake for less daily driving problems. This was about 25 years ago, I think I made a good choice.
 

junkyardhero

Well-Known Member
Joined
Jan 23, 2005
Messages
302
Reaction score
391
I'm not sure what I actually have on the car now intake wise, but talking here I think it is a cast iron Super Six. It is missing the stock linkage and I think I read that it needs a shorter throttle cable. It also has some sort of Loco kick down cable and adapter. Seeing that it all works as is and the Clifford needs many more pieces to come up with, I think I'll save the money now and try and find a smaller carb.
Thanks
post up a pic of what you've got. it might be that you've got all the jam stuff it just needs some love to work right.
 

dave ellis

Well-Known Member
Joined
Dec 30, 2012
Messages
248
Reaction score
34
Location
jacksonville, florida
I'm not sure what I'm looking for, but I want to up the performance of my Slant Six. I'm not sure what is entailed but I assume it involves intakes and headers. Which of these intakes is a good choice? I have a Holley 4412 carb and the 2 barrel intake.
Thanks

View attachment 1716009412

View attachment 1716009413
If you really want something different I have an adapter that will bolt to a four barrel manifold onto which you can mount two two barrel carbs
 
Top