Intake help needed
Thread Starter
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Senior User
Joined: Dec 2000
Posts: 476
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From: Az
Intake help needed
I have to smog my 78 f-150, but have run into problems. I live in California. It's an out of state truck,so it only requires egr for visual.
I have an edelbrock 4barrel intake, and a 600 cfm 4 barrell carb. The problem is we don't know the original egr valve for it.
We called edelbrock,who said use a spacer, and throw on a 75 egr valve. it doesn't work with it. It runs much rougher with the spacer, and runs perfect without it. It's drawing air from the front venturies, which is not supposed to. But, when mounted, the spacer plate overlaps the sealing lip,thus,causing a massive vacuum leak. This edelbrock intake is designed with an egr provision built into the back of the intake, ie the egr mounts directly behind on the intake behind the carb.
Our options are
1) find a factory 4 bb intake for a 75-79 351/400 (I've tried everywhere today)
2) track down the right egr valve (over 300 listings for a 75 only)
3) pull the 4 bb, and revert to the 2bb.
If anyone could shine some light on this, I'd be forever grateful!!
I have an edelbrock 4barrel intake, and a 600 cfm 4 barrell carb. The problem is we don't know the original egr valve for it.
We called edelbrock,who said use a spacer, and throw on a 75 egr valve. it doesn't work with it. It runs much rougher with the spacer, and runs perfect without it. It's drawing air from the front venturies, which is not supposed to. But, when mounted, the spacer plate overlaps the sealing lip,thus,causing a massive vacuum leak. This edelbrock intake is designed with an egr provision built into the back of the intake, ie the egr mounts directly behind on the intake behind the carb.
Our options are
1) find a factory 4 bb intake for a 75-79 351/400 (I've tried everywhere today)
2) track down the right egr valve (over 300 listings for a 75 only)
3) pull the 4 bb, and revert to the 2bb.
If anyone could shine some light on this, I'd be forever grateful!!
Last edited by bigblu; Aug 25, 2003 at 04:47 PM.
Posting Guru
Joined: Aug 2000
Posts: 1,127
Likes: 3
From: (near) Denver USA
Intake help needed
There are no factory 4V intake manifolds for the 351M/400 engine because they were never factory equipped with a 4V carb. Therefore, you will have to at least get a 2V-4V adapter and switch to a 2V carb to pass CA emissions.
The EGR valve should be mounted to the manifold directly, with no spacer under the carb (except the 2V-4V adapter). Apparently the tech guys at Edelbrock didn't understand which manifold you had.
Check this page for the correct EGR valve part number for your truck:
http://home.earthlink.net/~bubbaf250/parts/parts05.html
BTW: if the EGR valve part is obsolete from Ford, you can use the Ford part number to cross-reference the correct aftermarket replacement.
The EGR valve should be mounted to the manifold directly, with no spacer under the carb (except the 2V-4V adapter). Apparently the tech guys at Edelbrock didn't understand which manifold you had.
Check this page for the correct EGR valve part number for your truck:
http://home.earthlink.net/~bubbaf250/parts/parts05.html
BTW: if the EGR valve part is obsolete from Ford, you can use the Ford part number to cross-reference the correct aftermarket replacement.
Thread Starter
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Senior User
Joined: Dec 2000
Posts: 476
Likes: 0
From: Az
Intake help needed
Well, Edelbrock said we'd just need an adapter to bolt the egr to the intake. The problem is finding an egr that the center to center bolt hole is 3".
We've been on the phone all morning, and haven't had any luck.
We've been on the phone all morning, and haven't had any luck.
Lead Driver
Joined: Nov 2000
Posts: 6,650
Likes: 352
From: Albuquerque
Intake help needed
Originally the engine came with a 2V, a plate under that with the vacuum diaphram mounted on the back. With a 4V manifold you would have to use the 2v carb on an adapter with the factory plate in between.
The only other option I know of is to replace the manifold with the EGR version of the same thing. It has the boss and passages built in.
The only other option I know of is to replace the manifold with the EGR version of the same thing. It has the boss and passages built in.
