Offenhauser four-barrel Intake

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   I have been looking for this intake over the internet and I have found four different models. The price on them fluctuates between 310 and 330 dollars. 

This is the intake model List: 

6257DP Offenhauser Dual Port Intake Manifold
5999DP Offenhauser 360 Degree Single-Quad Dual-Port Intake Manifolds 
6258C Offenhauser C Series Intake Manifolds (Single Port)
6208C Offenhauser C Series Intake Manifolds (Single Port)

All of them are specified for AMC cars except for the 5999DP which is also specified for Jeep vehicles. 

Three of them are only specified for the 258 six only while the 5999DP one also specifies the 232 and 199 engines. 

The main question is: which of these four models should I choose?

I have a friend with a 1973 VAM Javelin with a stock 282 six and an A998 automatic transmission. He asked me for some help with converting his car into a VAM Go Pack replica unit. This means a four-barrel intake manifold, four-barrel carburetor, headers, dual exahust, camshaft and ported head. 

This is entirely a performance-oriented project. 

What carburetors can be used with this intakes?

What I've seen in all four models is that they are noted as "not for use with automatic transmission application". Why is this?

What does single/dual port means?

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Rambler Mexicano Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Mar/05/2011 Location: Guadalajara Status: Offline Points: 977	Post Options Post Reply Quote Rambler Mexicano Report Post Thanks(0) Quote Reply Topic: Offenhauser four-barrel Intake Posted: Apr/08/2017 at 10:57pm
	I have been looking for this intake over the internet and I have found four different models. The price on them fluctuates between 310 and 330 dollars. This is the intake model List: 6257DP Offenhauser Dual Port Intake Manifold 5999DP Offenhauser 360 Degree Single-Quad Dual-Port Intake Manifolds 6258C Offenhauser C Series Intake Manifolds (Single Port) 6208C Offenhauser C Series Intake Manifolds (Single Port) All of them are specified for AMC cars except for the 5999DP which is also specified for Jeep vehicles. Three of them are only specified for the 258 six only while the 5999DP one also specifies the 232 and 199 engines. The main question is: which of these four models should I choose? I have a friend with a 1973 VAM Javelin with a stock 282 six and an A998 automatic transmission. He asked me for some help with converting his car into a VAM Go Pack replica unit. This means a four-barrel intake manifold, four-barrel carburetor, headers, dual exahust, camshaft and ported head. This is entirely a performance-oriented project. What carburetors can be used with this intakes? What I've seen in all four models is that they are noted as "not for use with automatic transmission application". Why is this? What does single/dual port means?
	Mauricio Jordán Cuando no se es una empresa famosa se deben hacer mejores automóviles. - Vehículos Automotores Mexicanos S. A. de C. V.

DaemonForce Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Jul/05/2012 Location: Olympia, WA Status: Offline Points: 1070	Post Options Post Reply Quote DaemonForce Report Post Thanks(0) Quote Reply Posted: Apr/08/2017 at 11:26pm
	The 282 was a variant of the 258. It makes sense that the 258 intake would be the most useful candidate. Though exhaust probably leaves something to be desired. I know the 282 used the same crank as the 258, seeing how I essentially created a 285 out of the same crank and max bore 4.0L block. What does the head look like? Siamese #3 and #4 exhaust ports? Large independent bores?

goul6891 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Aug/05/2010 Location: Anchorage, AK Status: Offline Points: 60	Post Options Post Reply Quote goul6891 Report Post Thanks(0) Quote Reply Posted: Apr/09/2017 at 2:34am
	'not for automatic transmissions' because the carb is mounted 90° from stock on the dual plane, so kickdown linkage doesn't work. Easy fix is a cable kickdown instead of factory rods and cranks. Lokar makes them, and knockoffs are available too.

farna Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19692	Post Options Post Reply Quote farna Report Post Thanks(0) Quote Reply Posted: Apr/09/2017 at 7:49am
	I think the 5999DP is for the older models that have the exhaust manifolds attached to the intake, and the 6257 is for later models. The single port older number should be for the older also. You can make an older one fit with headers or later exhaust though. You have to cut the inner part of the exhaust manifold flange off. You lose the heat from being attached to the exhaust manifold, but no big deal. I've run one like that.
	Frank Swygert

tyrodtom Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Sep/14/2007 Location: Virginia Status: Offline Points: 6214	Post Options Post Reply Quote tyrodtom Report Post Thanks(0) Quote Reply Posted: Apr/09/2017 at 9:52am
	The pictures I've seen of a 252-282 head shows that the middle two exhaust ports are siamesed just as the 199-232 and 258 are. The Dual-Port feature has the primary and secondary sections of the carb outlets separated all the way to the head . The Primary section is small, which keeps the inlet flow velocity higher, giving better throttle response at low rpm. But it only works if you have a carb. with primary and secondary venturies , and use a gasket that keeps them separated at the carb to intake mating flange.
	66 American SW, 66 American 2dr, 82 J10, 70 Hornet, Pound, Va.

farna Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19692	Post Options Post Reply Quote farna Report Post Thanks(0) Quote Reply Posted: Apr/10/2017 at 5:56am
	Right -- only works with a 4V carb, and if you use a spacer it must be a four hole type, not one big opening.
	Frank Swygert

Ruby loye Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Jul/15/2012 Location: wa state Status: Offline Points: 792	Post Options Post Reply Quote Ruby loye Report Post Thanks(0) Quote Reply Posted: Apr/10/2017 at 6:25am
	Does the exhaust manifold have two pieces for the dual exhaust? That must hard parts to find. Mark

farna Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19692	Post Options Post Reply Quote farna Report Post Thanks(0) Quote Reply Posted: Apr/11/2017 at 5:48am
	The Clifford 258 header is a split three into one design. You can run it as dual exhaust or get a piece that brings the split into a single. Can't recall if they sell that piece or your exhaust shop has to make it. They just make a short tube header so one fits cars and Jeeps. I take that back... they show a long tube single exhaust header for pre 72 car sixes in a combo kit (header/intake/Weber 38 DGS carb). I would assume you could buy the header alone, but they don't list it separately. Might be an old photo though.
	Frank Swygert

232jav3sp Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Jan/09/2013 Location: Texas Status: Offline Points: 2451	Post Options Post Reply Quote 232jav3sp Report Post Thanks(0) Quote Reply Posted: Apr/11/2017 at 9:39pm
	If you are going to be running high RPM the single plane "C" series is recommended for that. Otherwise, I'd go with the dual plane. Just put a waterheated Offy dual plane on my Rambler this past weekend. Used a 500 CFM Carter and an Eagle exhaust manifold. Working very well.

Rambler Mexicano Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Mar/05/2011 Location: Guadalajara Status: Offline Points: 977	Post Options Post Reply Quote Rambler Mexicano Report Post Thanks(0) Quote Reply Posted: Apr/11/2017 at 10:06pm
	Thanks for your responses guys. I didn't know anything about the single port/dual port features of four-barrel carburetors/intakes. Since I've always worked around two-barrel carbs (Motorcraft 2150 and Holley 2300 for the most part) I don't have the same knowledge/experience with 4V units. The exhaust manifold is not a problem here since my friend will install headers in this car, so both parts will be separate. Going back to the single port/dual port aspect, choosing what intake has one feature or the other depends on the carburetor? Am I correct? If I buy a carburetor with a dual port feature, then that's the intake I'll be buying and viceversa. My friend wants to squeeze as much as possible from the engine at normal conditions (no turbo, no nitrous, etc.) From what you tell me, the dual port one is the correct for my application.
	Mauricio Jordán Cuando no se es una empresa famosa se deben hacer mejores automóviles. - Vehículos Automotores Mexicanos S. A. de C. V.