4.5 carbed 2bbl. Want 4bbl. intake. Help!

I have a 1991 4.5l mated with a 2bbl. carburetor, and I want to upgrade the upper intake to accept a 4bbl. carburetor.   Does anyone know what 4bbl. intake I could get that would mate with this engine?  Would the 1990 Fleetwood 5.0l 4bbl intake fit?  Or something else?
 
Thanks!

i had no idea that there were ANY carburated 1991 GM engines.
is this a mod or a foreign?

quote:

ORIGINAL: bpauly

I have a 1991 4.5l mated with a 2bbl. carburetor, and I want to upgrade the upper intake to accept a 4bbl. carburetor.   Does anyone know what 4bbl. intake I could get that would mate with this engine?  Would the 1990 Fleetwood 5.0l 4bbl intake fit?  Or something else?

Thanks!

Modified.  It is a stock Allante 4.5, with a Champion 2bbl. carburetor on top.

you got MY interest. 

is it an Allante engine on another model or an Allante car we got here?

quote:

ORIGINAL: bpauly

Modified.  It is a stock Allante 4.5, with a Champion 2bbl. carburetor on top.

Katzmans Caddy

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Ok, I am not an expert on every engine ever put in a Cadillac but are you sure you have a 2 bbl carb on that 4.5 V8 ?  Do you have a photo so we can see the set up? I have an idea but would like to see it. The 5.0 V8 will be a Chevy or Olds so nothing will be in common to the Cadillac 4.5 V8.

< Message edited by Katzmans Caddy -- 7/23/2007 11:14:40 AM >

Katzmans Caddy

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Well I thought they had throttle bodies or SFI (fuel injection). Throttle bodies do look like a 2bbl. Anyway my initial idea was this.......the engine is the same as the 4.1 only bored, if the 4.1 came with a 4bbl you would be able to get an intake from a 4.1 and use it. I think that 4.1 dates back to 1986 or so, maybe they had carbs. Failing that you could either buy a 2bbl to 4bbl adaptor or make one. Edelbrock sells these for the mainstream applications, read that as Chevrolet small blocks. If you already have an adaptor for the two barrel part of your engineering is done for you.

< Message edited by Katzmans Caddy -- 7/23/2007 12:31:43 PM >

Sorry about the delay in the reply, but the car came back from the painters' today and looks great!

Here's some more detail - it is an Allante 4.5 with an aftermarket Chamion 2bbl. carburetor mated to it (custom adapter).  It is being used in a 1986 Fiero GT.  It appears the only way to get a 4bbl mated to this 4.5 intake is to do some heavy machine work on the intake to adapt for the 4bbl flow.  I was wondering if there were any earlier carbureted model intakes that would take a 4bbl, or even a matching Chevy intake I could use?

Any ideas?

Thanks!

----- Ben

Photo #1 ...  I hope.


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Photo #2.


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The 4.1L has, unfortunately, a 2bbl TBI unit exclusively (mine's running a 5.0L/305 Chevy unit - best mod I ever made to that thing).  The aftermarket does sell adapters to mate a 4bbl carb to a TBI intake and vice-versa.  Check Jegs or Summit Racing - you may have to call them to find what you're looking for. 

To run carb(s) I would suggest to get allante intake bottom.Fabricate runner section allow for adjustment of runner lenght it's important in terms of performance.Fabricate plenum and base for carb(s) to mount on, from sheet aluminum.Volume or size of plenum is also important. There will alot of trial and error to get it right. This was how the original sbc tunnel rams were developed using the FI manifolds in the 50's were made.