i got a 400 for a 81 in a 86 f250 with a c6 4x4 1345 bg transfer case. im hoping to get a lot of input and get educated on what is the best spacer to use on my 400. i have a edl intake and a edl 600 or 650 cfm carb. i believe its the 650 4bbl. i was told by adding a 1 inch spacer with the four holes will give me a little better low end torq plus help to get read of the slugsh start when you stump on the gas. they said 1 inch was all i need but damn i can get one in two inchs. wouldnt a bigger spacer increase the performance more?
and help and links to good info on this subject will be very helpful. plan on buying a spacer tomorrow and having it on this weekend.
thank you

 

oh i got about 6 thousand miles on the engine and 3 thousand on the tranny

 

this is what i have on my engine.

edl 1406
Number of Barrels: 4
Carburetor Flange: Square bore
Choke: Electric
Fuel: Gasoline
Secondary Type: Air valve
New or Remanufactured: New
Fuel Inlet: Single
CFM: 600
Carburetor Finish: Silver
Ford Kickdown: No
Throttle Linkage Type: Universal
Quantity: Sold individually.
Notes: Mild performance, calibrated for economy.

my intake
edl 2172
Brand: Edelbrock
Product Line: Edelbrock Performer Intake Manifolds
Engine Block Style: Stock/OEM standard deck
Carburetor Quantity: Single
Intake Style: Dual plane
Basic Operating RPM Range: Idle-5,500 RPM
Intake Finish: Natural
Intake Material: Aluminum
EGR: No
Quantity: Sold individually.

Intake Manifold, Performer, Dual Plane, Aluminum, Natural, Square Bore, Ford, 351M/400, Each

Check to make sure this part fits your application
Low-end torque with improved throttle response.
Edelbrock Performer intake manifolds are low-rise, dual-plane designs with patented runner tuning and a 180 degree firing order you won't find with the competition. This combination boosts torque over a wide rpm range, from idle to 5,500 rpm. These manifolds also deliver improved throttle response over stock intakes and are available in both EGR and non-EGR styles. Many are 50-state street legal.

 

I have used a 4 hole 1 inch spacer with good results

 

Running a 1 or 2 inch spacer with the 4 holes works great for low end torque.

 

I agree I have a 1" spacer with 4 holes on my Edelbrock intake. It made a big difference on the low end.

 

I'm told by a top engine tuner I know that the best carb spacer on the market is:
Summit Spiral-Bore Phenolic. They make one for square-bores, and one for spread-bores. Their $89.95 ea. I'm told there worth the price, in mileage and horsepower. This tuner uses these and has flowed 750CFM out of a 600CFM Holley carb. And with this spacer has gotten up to 15-16 MPG out of a 460 in a 4x4. I shared some of this late last year when he did some work on my 460 4x4.

 

I am with the rest...from my real world experience a 4 hole 1" spacer increased the low end of the power range with little to no effect on the top end. I use a plain old aluminum one.

Kenny

 

well i went to advance and order a plastic two inch spacer. i was talking to a buddy there and he kept telling me the bigger the spacer the better fuel air mixture i will get and the better performance that will come along. so he talked me out a 1 inch spacer to a 2 inch. im going to pick it up now and put it on. ill let everyone know what i think. thanks for the help

 

well got the 2 inch spacer and put it on my truck and damn im very happy with it. it has awesome pick up and go, runs the gears better inbetween shiftin, and allowes me to pass people faster. i only wish i put this on 6 months ago when i dropped the engine in.

does anyone know if this 2 inch spacer going to help gas mileage or make it worse?