I am in need of some advice. its time to choose my fuel system and I am tossing around the speedway 3x2 offy intake setup with the super 9-7s, or just going with a 4 bbl carb. Can I get some pro's and con's? I really do not know the difference. Any input would be appreciated.

 

The 3x2 is an old Hotrod staple - They are also a real pain to tune and and keep adujusted - They also like a built motor - A lot of folks block off the front and rear and run on the center (Wich you do anyway if you dont have your foot in it)
The 390 CFM 4 bbl is easier to tune and again without a lead foot it will run on the 2 main and keep the secondaries fro go power - It is friendlier to a built motor also.

 

The 3x2 looks cool and comes with great names like six pack and three dueces. Three air cleaners look cool too. You see four barrels every where while 3x2s are rare. But there's a reason for that. A 4 barrel e Brock or Holley is a set it and forget it set up while the triplets always seem to need fiddling. If looks are most important go with three pairs. Otherwise a four is the way to go, at least until you fuel inject it.

 

thanks for the reply's, I have not considered fuel Injection. I have a FLHD bored out, using the 296 CI Scat stroker kit, isky Max 1 cam and OFFY heads, Price difference between the 4 barrel setup and the 3x2 is abought a $1k, thats complete intake carbs etc...no idea what F.I. cost. That is not my deciding factor but it is enough to ask the questions. its not for show as I will be driving it more than just sundays.

 

Use the 4-barrel, you'll thank yourself later.

 

Not so. IF you have the secondaries set so they don't leak air, have matching parts in them, and the primary is built correctly, they work just fine. Ford, Mercury, Dodge, Plymouth, Cadillac, etc. all used factory 6V, Tripower, Sixpac, you name it setups for many years, with no problems.

If you are going with a 3X2, you want progressive linkage with the center carb as the primary, and the ends as dumpers (no idle circuits). You will most likely need a different distributor as the vacuum signal will be off kilter when the other 4Vs open up.

In most tests, a four barrel will outperform a 3X2, but a nicely built 3X2 will outshine it!

 

I have had two 94’s for years. Ran them on my F1, and now on my F4. I would run 94’s only if you have the time to keep them up. They can be a pain at times. But if your know that and spend the money to get good carbs to start with and make sure they are setup up for your flathead. Nothing look’s as good on a flathead.
I chose to run two instead of three for several reasons, one less carb to setup and buy. I could leave the generator in the stock location and for my build more than enough CFM.
On my race truck Holley style 750 Double pump on E85, sons street car Holley 650 double pump. Once you get these set up they are going to need very little work. What is it you want?
Tom

 

I'm partial to the 3x2 setup. There just COOL on a flathead. Performance difference does not sound big enough for me to notice, its just a cool street cruiser with gitty up when feeling froggy. A freind just mention using a 4 barrell and I saw the price difference which made me start the discussion. speedway has a completed Offy 3x2 intake setup wit progressive linkage just as 1952Henry stated. 98% going with the 3x2 just wanted input

 

If you go with the 3x2 setup be sure to also buy 3 NEWLY manufactured redesigned carbs that are matched to each other and to your application. Don't try to use a mix of carbs off 1x2 engines or any old stock. Virtually all the old carbs leak fuel and/or air so badly that you'll spend more time trying to keep them running right than driving.
There is a LOT to recommend FI, and there are setups that look like carbs. Put it in, tune it with your laptop and forget it. Much better mileage, running, throttle response, power and can be quickly retuned for however bad the gas continues to get.
May pay a little more up front, but will pay you back pretty quickly, and is more impressive to the gear heads than any amount of carbs.