Main Menu

4 Hole Plenum VS. Open Plenum Question

Started by Daveh, February 03, 2017, 06:38:04 AM

Previous topic Next topic

0 Members and 1 Guest are viewing this topic.

Daveh

Hi Guys,

I ordered some spacers for my small block MOPAR and instead of the open plenum I accidently ordered the 4 hole (See Attached). It's a street engine with an Edelbrock Thunder series 650 carb with a performer intake.  I'm trying to achieve the proper height because they are going on my 71 Challenger with a Shaker hood. Because of their price I want to try to make the correct decision first because if I experiment then I can't return them.


The main question - Will I notice a difference if I use them or should I send them back and get the one hole? Returning them is no problem they told me they will just exchange them. What are your thoughts? Thanks

Dave


Brads70

My thoughts are... I'd go with the open one so I don't have to worry about a throttle blade hanging up and keeping the throttle wide open. People often remove part of the divider for more top end anyhow. 

Cuda Cody

Maybe @Chryco Psycho  has some experience with this, but I too would opt for the open one in your situation.  But not 100% sure.   :notsure:


303 Mopar

 :iagree:  Your best bet is going with open, but I doubt you will see any major difference in performance since your intake is already dual-plane.

Daveh

I just dropped them in the mail to return them for the open plenum spacers.  Thanks guys. 

HP_Cuda


Definitely the open plenum, no need to restrict or hang up on anything.

If this was the case you would also use the 4 hole gasket too!  :D
1970 Cuda Yellow 440 4 speed (Sold)
1970 Cuda clone 440 4 speed FJ5
1975 Dodge Power Wagon W200

GoodysGotaCuda

Edelbrock clearly recommends the FOUR HOLE style spacer in their carb documentation for low/mid torque and throttle response.


Sent from my iPhone using Tapatalk
1972 Barracuda - 5.7L Hemi/T56 Magnum
2020 RAM 1500 - 5.7L

My Wheel and Tire Specs


RUNCHARGER

Divided plenum manifold? Yes I think I would have kept the 4 hole.

Sheldon
Sheldon

HP_Cuda


Maybe the problem begins with using an Edelbrock carburetor?
1970 Cuda Yellow 440 4 speed (Sold)
1970 Cuda clone 440 4 speed FJ5
1975 Dodge Power Wagon W200

Chryco Psycho

basically the open spacer will work better in a situation where the engine is under carbed this will allow all four barrels to feed any given cylinder
the 4 hole increases signal to any one venturi & will improve response which helps if the engine is over carbed
a 650 cfm carb is n the small side for any engine except the 318 so the open spacer would be my choice  :alan2cents:

Cudakiller70

I went with the 4 hole, reading better signal for street. My thinking was if I didn't like it I could cut it open.