Edelbrock 1406 & 1411 Installation Summary
Note: My final and best solution on the carb installation is presented here however you can see the history of the different things I tried by Clicking Here
From the factory a heat riser is closed during cold startup forcing exhaust gases across a center channel in the intake with an internal choke tube causing the engine to heat up faster, improving air/fuel mixing, and heating air drawn into the heat tube from the bottom of the intake causing the carb to go off choke as the engine heats up. The aftermarket Edelbrocks, with it's electric choke, does not use the internal choke tube, and does not need the 300+ degree heat under the carbs base. In addition it has been my experience that even if the heat riser butter fly is removed there is still 300 degree temps at the center of intake from bypass gases and can potentially cause vapor lock under certain condition. It has been my experience that completely removing the exhaust gas heat from the intake provides the best condition for optimal performance of the Edelbrock carbs.
Below are 3 easy steps to eliminate the exhaust heat form the equation:
1) Remove butterfly from heat riser, or install spacer, or remove heat riser spring and wire or weld open, or install new exhaust pipe eliminating heat riser. The factory heat riser is closed during cold set-up. Since step 2 below blocks the exhaust channel across the intake, the left side exhaust would not have anywhere to exit until engine heats up causing tremendous heat and back pressure potentially causing catastrophic engine failure.
(see picture 1 below)
2) Place blocker plates at center exhaust port between cylinder head and intake manifold. I used thick galvanized roofing steel with the thicker intake gaskets sets (not the metallic gaskets). NOTE: I recall someone saying there are exhaust gaskets available with block plates included but my searches have come up empty.
(See picture 2 below)
3) Replace original intake to carb spacer with PCV nipple with 3/8" insulator spacer. I used a Trans-Dapt TRD-2446, however, there are other brands on the market. 3/8" seems ideal height, especially if you want to use the stock air cleaner and the adaptor sold by Russ Austin. If you are running an aftermarket air cleaner and have additional height clearance to hood, you might consider a taller spacer for even better air/fuel mixing and dispersion.
(See picture 3 below)
NOTE: You do not need to remove the internal choke tube, or block choke tube ports at end, or the top of intake channel ports if you do steps 1 and 2 above. In my Carb project I started by trying to block the intake at the 2 top channel ports and the 2 ends of the internal choke. If you stop the flow of exhaust gas at the cylinder head to intake, you do not have to worry about anything else. This would be useful if your internal choke tube is intact and solid and might want to reuse the intake manifold in a stock application later on.
Electric Choke Wiring
You need a 12 volt switched source. For 1964 Cadillacs with the Tubo Hydramatic you can simply tap into the pink wire that goes to the kick down switch at back of carb. For all 1963's and 1964 with the Hydramatic you will need to run a wire into the car and behind the dash to tap into the pink ignition wire.
TV Rod Connection (all 1963's and 1964's with Hydramatic transmission)
You will need to adapt a plate to the Edelbrock throttle plate to connect the TV rod from the transmission. This helps control shifting on the Hydramatics and is not optional. The TV rod plate from a Carter AFB can be modified to attach to the Edelbrock. Others have posted information on the Website
Transmission Kick-down Switch (1964's with the Turbo Hydramatic)
The 64's with the THM transmission had a kick-down switch mounted to the left rear of the factory Carter AFB and Rochester 4GC. The Edelbrocks do not have a mounting block on the carb for the switch and you will need to adapt a switch to the carb and accelerator linkage in order to provide the kick-down function while using the Edelbrock. NOTE: I have ran my 1964 Coupe de Ville with the Edelbrock for 10+ years without a kickdown switch with no issues. the big 750 cfm coupled with Pertronix ignition has provided me plenty of power to get up and go when I need to pass with out that feature. IT IS on my to do list but has not been pressing and definitely consider that an optional item.
Air Cleaner Housing - Using Stock Air Cleaner (see picture 4 below)
Since the top of the Edelbrock is 5 1/8” wide and the original air cleaner housing neck is about 4 3/16” to fit the Rochester 4GC or Carter AFB you will need some sort of adaptor to use the original air cleaner. Russ Austin sells a never nice high quality adaptor that raises the air cleaner 1 3/16”... which just clears the hood if using a 3/8” intake to carb spacer. If you go any higher the air cleaner will probably hit to hood.
Porting Intake Manifold for 750cfm Edelbrock 1411 (see picture 5 below)
The front primaries on the stock intake are considerably smaller than the venturi and butterflies on the Edelbrock 1411 and performance can be gained by porting the front intake primaries to match the Edelbrock. My local machine ship ported mine which can be see in picture 3 below.
NOTE: The 1411 will not bolt directly to the stock intake as the front butterflies will hit. You would not want to do this anyway since you want to use some type of insulator spacer to replace the factory spacer as noted previously.
Fine Tuning the Carb using Calibration Kits (see picture 6 below)
Performance can often be tweaked by changing out the jets, metering rods and/or step-up springs. You can get calibration kits from Edelbrock that has an assortment of metering rods, jets, and step-up springs.
- The kit for the Edelbrock 1406 600cfm carb is the 1487 kit.
- The kit for the Edelbrock 1411 750cfm carb is the 1489 kit.
NOTE: I ran my 1411 on my 1964 CDV for at least 5 years without changing anything. I later did some experimenting and ended up running my carb a bit richer using different metering rods only which was a very simple mod. See my history link for more details. I had briefly installed a 1406 600cfm and it also ran fine out of the box.
The Bottom Line is I consider rejetting optional. Get everything running like you want it as set up out of the box and then if you like purchase a Calibration Kit and take baby steps to run leaner then richer, and try changing out the step-up springs. The Edelbrock owners manual has great info on how changing these out the jets, rods, springs may affect performance and includes nice charts to see exactly how these changes will affect the carb specs. It also goes into detail regarding other aspects of when you might consider recalibration such as using a longer than stock duration cam.
(Picture 2: Plate to block center exhaust port)
If you have a 63 390 with the transmission rod that shifts the trans -on the carb
If it was my own car --i would stay with that carb and have it rebuilt --due to you otherwise having to adopt a plate for the Edelbrock to work the trans correctly --if you are capable of doing that fine
Car in my family from day one -off the showroom floor
I have had both the AC idle up and the kick down switch on the stock carb disconnected for many years
Both of which are not necessary in my own opinion and making the change to the Edelbrock an easy change for most regarding these two carb add ons
The 429 behind the TH400 will just about pass anything at any speed without the kick down ( passing gear )
Seems it is always --kicking the passing gear that has damaged most automatic transmissions i have managed to break ( not saying the Th400 will break doing that )
Just the down side of being hard on our cars
The driveshaft will always be the weak link in the drivetrain as i see it ( those U joints )
( Carter on 64 429 -to Edelbrock 1406 electric choke )
Jason do you have a number I could contact you on? Thanks Michael
- The same spacer will work fine.
- Transmission vacuum modulator attached to back of Edelbrock in same way it attached to back of Rochester... via the large vacuum fitting off very back of carb. It has a large male nipple that feeds brake booster and female connector that trans line screws to. Simply transfer from Rochester to Edelbrock. See picture of fitting below attached to back of my carb and then a pic of it removed.
- I think I just used copper spray gasket adhesive to hold block plates. Once torqued down it's not going anywhere.