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Suggestions on Holley spacer plate?

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I had been working on getting my AC charged on the 73 vert. Took forever to find the leak which was the high pressure Schrader valve at the service port. My AC compressor does not have the isolator valves just the hoses and hook up for gages. So I still have a leak somewhere that does not show up with black light so might be in the dash so I quit working on it.

This car sat for 27 years so I thought I would pull the Holley carb off. When I did I found a bad gasket or a wrong gasket. The PO lived in California and to keep it legal he put an EGR plate under the Holley configured for the spread on the Holley. The issue is that the Edelbrock 2-V head to 4-V intake does not have enough material to close off the EGR plate in the rear. So it had both a vacuum and exhaust leak going on. I thought it was a header gasket leaking.

The Holley had a list # of 7154 which I finally figured out was a 4150 model Holley. Summit had the best price for the rebuilt kit and also the transmission cooler and should be here today.

So looking for suggestion of spacer plate to go back with without the EGR port. The current plate is 7/8" thick and has 4 holes to match the Holley.

Is 4 hole better or one with just the big square opening? The intake has the one web in the center going front to back, see pic.

Carb Renew kit should be here today and I also ordered a Hayden fan cooled AT cooler to get the heat from the transmission out of the radiator.

I have been running the Lucas gas additive and the inside of the intake and the intake ports are all oily also. It did make a huge difference in the operating temperature of the engine.

Me and friend checked the vacuum on the engine at idle and it had 15 lbs. which surprised me with the cam that is in it. I have no idea of the spec or make of the cam. It does run good enough to turn the tires when it goes into second at about 50 mph.

It is amazing how many things the PO did wrong on building this car. I expect the engine to blow at any time but I have two more sitting on stands now so not going to worry about it.

Want to drive it to the MOM, Mustang Owner's Museum end of this month to all Ford show and the Carpenter Museum will be open that afternoon with the Hornet's Nest AACA club meeting there. That is about 250 mile round trip so I want to be more confident in the car.


When a man is in the woods and talks and no women are there is he still wrong??:P


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If that's the very intake you're using, then there is no EGR passage in the carburetor pad, so it couldn't be leaking exhaust by the carb.


You probably don't even need a spacer unless there is some sort of linkage clearance issue. I would run a thick base gasket to help insulate the carburetor from the engine heat.





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On a dual plane intake manifold i would go with the 4-hole design, this will keep the intake operating the way it was designed, as a 180° manifold. While some dual plane manifolds, like the Shelby Blue Thunder or some Edelbrocks, have the center divider notched or cut down some, it was tuned on dynos. You don't know what effects an open spacer will have, negative or positive.


Here is a good article:




“If you can't explain it simply, you don't understand it well enough.”

--Albert Einstein


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The manifold in the picture is not the one on the car. This is just one I picked up on a parts buying run for $35.00.

If you see in the previous picture that one is not machined for the plate that would have the choke heater installed. The one on the car was machined and has a plate over that area.

With the current EGR plate the throttle linkage is in alignment and also the transmission kick down works fine so I wanted to keep it at the same level.

Thanks for the link to the info. I had also talked to local racer and he also suggests with a dual plane to have a plate with holes is better.

One thing I think is odd is that the holes through the current plate are on an angle??

I am going to use just the narrow gaskets at the connection to the head not the turkey pan. I am going to cut the old turkey pan off and use it as a heat barrier under the intake. The narrow gaskets are much cheaper also.

I doubt you can see in this pic but it has the EGR plate and heat isolator and the cap is on the choke heat riser opening in the manifold.

I also got a different air cleaner because this one sat on top of the MSD wires and would arc out. I got rid of the tee handle bolts on the valve covers long ago.

I also have to find a place for the transmission cooler I do not really want it in front of radiator. It has it's own fan that can run either push or pull so will look for place under floor maybe. Ordered not painted but came painted? It is not small probably 12" square.


When a man is in the woods and talks and no women are there is he still wrong??:P


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The only spacer plates I've seen with angled throttle bores were the adapter style that allowed you to bolt a square bore carb onto a spreadbore intake, or vice-versa. Looking at your intake, it's seems to be a square bore carb pad. The EGR intakes I remember were the Holley Street Dominators that had the EGR pad at the rear of the intake and this is clearly not one of those.


What intake in currently installed on the car?


How about some pics of the spacer off the car and the carb pad on the intake? Any part numbers on the spacer?


IMO, just run a phenolic 4-hole spacer of close to the same thickness as what's installed.



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i run the same intake with a 4 hole spacer with a holley.

i needed the spacer for the clearance between the intake for the holley. i think i had to put a 1" spacer but i don't remember now.

i use a Phenolic spacer just incase of vapor lock issues which i have not had.


only issue with the 4 holes is make sure your carb alignment is good so you don't get hung up on the butterflies opening and sticking on the spacer.

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On David's intake the planes holes are so big, I don't think it matters very much if full open or 4.

What would be the diff if any?

73 modified Grande 351C. (Finally back on the road woohoo!) 

71 429CJ. ( In progress )

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It's not the size of the holes, but in keeping the two sides of a dual plane manifold separate. You can read how dual plane and single plane manifolds function in the link n post #4.



“If you can't explain it simply, you don't understand it well enough.”

--Albert Einstein


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Hemikiller wanted to see some pictures of the EGR spacer plate that was on the car so I got some yesterday.

I did order a new plate due in today. Was shocked that no parts house in town keeps plates or gaskets in stock for the Holley.

I decided not to fool with trying to cut the turkey pan gasket up to use as a heat shield just put the narrow gasket between head and intake.

This car came from California and I suspect that 27 years ago you still had to have the emissions stuff on the car for inspection. So he put the EGR plate on which did not seal off on the rear of the intake surface. There was not enough flat machined area. He had plugged the connection on the front of the plate and put the cover plate on the heat riser on the R.H. side middle of the intake.

The other intake has the same casting numbers and info but was not machined for the EGR hook up. I just bought it because the guy only wanted $35.00 for it and they cost $332.95 on Jegs now. He had put on a Mustang and crashed it the next week.

So if you do need one with EGR they do make them.

The holes in the EGR to clear the butterflies are on a slight angle few deg. I guess being a tool & die maker for years I could see it. If you put a scale inside the hole you can see it is not bored perpendicular to the surface.

Missed last night cruise in on our Main Street. They shut the street down for two blocks and park old cars and dance in the street and have live bands. Since I did not have the new plate I could not go.

































When a man is in the woods and talks and no women are there is he still wrong??:P


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With your dual plane manifold you should be fine with a 4 hole spacer

I had some vacuum/idling issues using a phenolic 4 hole spacer on my RPM Air Gap which has the notched out plenum divider

Ended up getting the aluminum one below designed to use with dual plane intakes especially the air gap

They even machined 1/4 inch off it to give me better hood clearance and works a treat



carby spacer.pdf

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That's Edelbrock EGR plate, and neither of those intakes have the EGR passage, so you can throw that puppy on the shelf.







I know it didn't have he the plate to run the tube to he took off after inspection and put the cap over the opening machined on the R.H. side to the exhaust. In California at the time 27 years ago when he put it on you had to retain the EGR or not pass inspection.

Here in N.C. there is no inspection for anything if 35 years old, no safety no emissions. I replaced the EGR plate with just a solid 1" thick from Edelbrock yesterday and if anybody needs the EGR plate to be legal will sell for sure.

Since there was a vacuum leak under the EGR plate it was causing a surging while going down the road which is gone now.

So now to go back to the AC to find that pesky leak.

When a man is in the woods and talks and no women are there is he still wrong??:P


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