Ok so I have been itching to do something new with my 300 for a couple years and i would like to try and make a custom intake, possibly with 3 horizontal carbs, I can weld, and am fairly good with small fab projects, what material am i using to make this? and can i do this with my little mig welder? reason behind this is i want something unique. If this isnt a good idea for some reason let me know. Ill take all and any advise. Or new ideas. Thank you.

 

Sometime back, The Frenchtown Flyer shared this photo, which was made from the center sections of three original log type intake manifolds, with the open areas brazed [I believe] and a balance tube connecting each section. Original Carter YF or YFA carburetors can be used. The neat thing about this set-up is that a plate can be made for the bottom of each of the sections and engine coolant can be routed to flow through each to add heat to the underside of the carburetor.

 

Or, one can fabricate a piece like this to attach to the bottom section of a 1987 - 1996 F.I. manifold. The missing top piece in the photo is a flat plate which can be made to orient single or multiple carburetors.

 

This is something I would like to do on a performance 300 six but I was thinking more along the lines of Velocity Stack injection.

Side draft carburetors can certainly be used but the spacing between the carb pairs is less than the 300 six 4.480" spacing. Not a big deal but I prefer the runners to be straight.
For a classic side draft look I was looking at the Jenvey Heritage Throttle Body but again the spacing doesn't match.

My thoughts were to make 2 triple 50mm throttle plates out of a aluminum attached to the runners that hold the injectors and are welded to the plate that bolts to the head.
The velocity stacks bolt to the front of the throttle plates.
Since there are 2 triples you would use center pull throttle linkage and the TPS would mount on one of the ends.

Any of the stand alone aftermarket EFI systems could be used.

Non of the above is cheap but sure would get plenty of attention.

Is you engine stock?

 

Very cool, I thought about using the bottom half of the efi intake but I'm still deciding what I want to do. I know I should have thought of this before, but are there any plusses to having multi carb set ups. I have read alot of posts about the max carb size for the 300 and it seems to be around 4 to 500. Even if I ran a 3 carb set up that equalled out to about 500 cfm. Would there be anything amazing about it except for fuel distribution.

 

Yes sir very stock. It has an ear delete and that is about the extent of it. I need brands of side draft carbs, get some stats and try to design a blueprint for it to see if I could make something work. My A/C blower box may get in my way

 

You would be looking at Weber DCOE carburetors.
Not sure if you would need three 40 or 45 mm carbs for a stock 300.
The actual airflow is determined by the replaceable throat or venture size.
I would call Redline and get their recommendation.

Independent runner carburetor sizing is totally different than carbs using an intake manifold with a common plenum

 

Clifford used to [and may still do?] sell these manifolds for side draft carburetors:

 

Not 3 carburetors, but currently available on eBay:

 

After some research into materials and carburetors i would like to use, it would cost far too much to home make my set up. i have heard from many people that the best thing other than the 1 bbl is a 4 bbl. i have heard 2 barrels are efficient and i have also heard that they are the exact opposite.

What kind of carb would you recommend and what intake. and what gas mileage do you get with it? right now i get about 12 ish mpg and i cant spin a tire to save my life.

 

2 X 4 Clifford w/ two 2100/1250s.

 

Looking at the least expensive combinations:
For a stock engine an Offenhauser "C" intake manifold and a 2bbl adapter with an Autolite 2100/2150 2 bbl 1.08" venturi will work fine.

As previously suggested, The second possibility if you want something unique is to use the bottom half of the EFI intake and make a plenum with a replaceable top for different carburetor combinations.




If you are looking for more power, after many combinations from dozens of forum members (Here and elsewhere) it is clear that there are no significant gains until the stock camshaft is dealt with.
Some have had reasonable gains by replacing the stock 300 1.6 ratio rocker arms with the Chevy six 1.75 ratio rocker arms but the biggest gains is found by replacing the stock cam with an aftermarket cam with more duration and lift.

 

That would be a great design for a turbo build with EFI.