Edelbrock LD4B ?s

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DartGTDan

DartGTDan

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I have an Edelbroack LD4B intake manifold I got off of E-Bay that I have a few questions about (please see photo).

#1 What is the hole in the rear of the manifold (between the Chrysler part number and the edelbrock "E") used for? Do I need it? If not, what should I "plug" it with? Would teflon tape on a pipe plug be enough? Will a pipe plug restrict fuel flow? Should I worry about the flow?

#2 I have an Edelbrock 1406 carburetor (currently on my buddy's truck so I can't measure it) to put on this manifold. Does the 1406 mount using the studs currently on the manifold, or will I need to move the studs to the inside holes?

#3 What size (length) are the thermostat housing mounting bolts? I have a couple of bolts that thread in about 3 full turns. Is that enough? If not, should I run a tap/die through the holes?

Thanks for any input & I'm sure I'll have more ?s
 

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That is a hole someone has added. It was not there originally. Whether you plug it or use it is up to you. I believe the Edelbrock carburetor uses the inside bolt pattern. On the thermostat housing bolts, Make sure the bolt holes are free of broken off bolts and chase them with a tap to clean them out. Then use an appropriate length bolt that will tighten the housing.
 
I would stud that t-stat. Reason being the bolts thread into aluminum and its much softer than cast iron. You know youll get some sort of metal reaction, just to be on the safe side. Pipe plug the hole with tape or dope.
 
I think you'll find the Eddy 1406 can use either set of holes....

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A Holley would use only the outter hole pattern....

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Cool. I had forgotten the Eddy had eight holes.
 
The inner set of holes would accommodate an earlier AFB. The outer set a Holley, AVS, etc... Your Edelbrock 1406 has both sets of holes so it will mount to an early AFB factory manifold.
 
DartGTDan said:
I have an Edelbroack LD4B intake manifold I got off of E-Bay that I have a few questions about (please see photo).

#1 What is the hole in the rear of the manifold (between the Chrysler part number and the edelbrock "E") used for? Do I need it? If not, what should I "plug" it with? Would teflon tape on a pipe plug be enough? Will a pipe plug restrict fuel flow? Should I worry about the flow?
Click to expand...

Agreed on the added hole
On the intake. Someone put it there as a vacuum hole. You do not need it. You can use the rear of the Edelbrock carb for that. Most likely vacuum port for the brake booster.
Just get the correct size plug and wrap Teflon tape around the threads twice and screw it in. The pipe plug should be short and not cause any flow issues even if it sticks into the runner.
Don't worry about this.
 
DartGTDan said:
#2 I have an Edelbrock 1406 carburetor (currently on my buddy's truck so I can't measure it) to put on this manifold. Does the 1406 mount using the studs currently on the manifold, or will I need to move the studs to the inside holes?
Click to expand...

It will fit. All the current Edelbrock carbs have enough holes to mount on any intake except the dominator series intakes.
I do very seriously suggest the use of an Edelbrock "thick" carb insulator gasket as this prevent heat from getting Into the carb and boiling the fuel.
 
DartGTDan said:
#3 What size (length) are the thermostat housing mounting bolts? I have a couple of bolts that thread in about 3 full turns. Is that enough? If not, should I run a tap/die through the holes?

Thanks for any input & I'm sure I'll have more ?s
Click to expand...

Those bolts are long enough. I would NOT stud the thermostat housing.
I do not know the exact length of the OE bolts. But 3 full turns provides enough clamping force to do the job.

Running a tap, not a die, is what you would do to clean the threads up in the bolt hole. It's not a bad idea and it should be done if there is resistance in installing the bolt by hand. It's bee a while since I have owned that intake. I do not remember if the bolt holes are blind or go into the water passage under the thermostat. If it does go into the violent passage, wrP the bolt(s) with Teflon tape.

That's a good intake you have there. I ran that with the same carb your going to put on there as well.

Oh, I forgot to mention, that water pipe at the front of the intake should be a simple straight up pipe for the heater hose.
 
I don't know why they put that extra hole in there as there is a plugged up vacuum hole right next to it.... :banghead:

Also keep in mind that there aren't any mounting bosses for your coil, like on a stock intake, so you are going to have to find a way to mount your coil.

I would go for at least 3/4" depth for the the thermostat bolt holes. 3 threads doesn't sound enough to me, especially as the first thread or two is usually slightly tapered and can't hold as much force as the non tapered threads. :rambo:


They are great intakes for the street on a little small block. :thumleft:
 
3 threads are enough, more is always favored.

An idea on coil bracket mounting.... Mount it to the wall with an existing bolt that is there, like the ECU bolts and just bend the coil bracket. A&Rengineering may have something for you as well that will look better.
 
Bolt length = thickness of thermostat housing + diameter of bolt (then round up to nearest bolt length) So for example, thermostat housing is 1/2" and bolt is 3/8" you want 3/8-16 x 1" bolts.

A general rule of thumb it the minimum thread engagement should be the diameter of the bolt, or one complete thread visible on top of the nut with washer compressed.
 
#1 hole is for a pipe fitting for a vacuum gauge. If your dash has the Performance Indicator, might as well use it. It probably takes a 3/8 NPT to 1/8 hose nipple.


DartGTDan said:
I have an Edelbroack LD4B intake manifold I got off of E-Bay that I have a few questions about (please see photo).

#1 What is the hole in the rear of the manifold (between the Chrysler part number and the edelbrock "E") used for? Do I need it? If not, what should I "plug" it with? Would teflon tape on a pipe plug be enough? Will a pipe plug restrict fuel flow? Should I worry about the flow?

#2 I have an Edelbrock 1406 carburetor (currently on my buddy's truck so I can't measure it) to put on this manifold. Does the 1406 mount using the studs currently on the manifold, or will I need to move the studs to the inside holes?

#3 What size (length) are the thermostat housing mounting bolts? I have a couple of bolts that thread in about 3 full turns. Is that enough? If not, should I run a tap/die through the holes?

Thanks for any input & I'm sure I'll have more ?s
Click to expand...
 
Thanks everyone for all your input(s).

I will try to find a pipe plug for the added hole (with teflon tape).

I do have a thick carb gasket to help prevent the fuel boil I've read about.

I will also borrow the appropriate "tap", from my work, for the thermostat housing bolt holes. I'm also planning on getting the appropriate heater hose nipples.

I already re-located the coil to the driver side fender when I added the electronic ignition.

Again, thanks for all the wisdom!
 
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