I'd like to hear some opinions regarding the BBD. I've just finished a Super Six/Dutra Duals setup in my auto '72 Swinger, and of course, it has me wanting more. I'm trying to establish some future goals to build on what I have without undoing what I've already done.

This is (and will always be) a street car, daily-driver, so I'm hoping to salvage as many mpg as possible, while bumping up the power. I'm looking at head work and a (custom grind) cam, along with a possible short block rebuild.

What are the horsepower limits of my BBD, without resorting to a 4bbl or EFI? What upgrades are recommended, and which ones would be a waste of time and money with a BBD? Just wondering...

VM

Well, the 318 and slant six BBDs flow 280 CFM. There was a BBD installed on 383s that shares the same bolt pattern that probably has a higher CFM rating. Later 70s BBD jets are supposedly interchangeable with Edelbrock jets, but I have never even heard of aftermarket metering rods for a BBD. The only downside to the BBD is the throttle shaft bushing problem. But get one rebushed and it is a reliable, simple carburetor.

If you are trying to balance street performance and MPG I would stick with the BBD or possibly bump up to a Motorcraft 2100 carb on an adapter. Or maybe the Holley 2305 if you can find one.

Hey, Reed.. All the 2bbl 383 BBD's that I have seen have the larger pattern like the Holley 2 bbl that was used on the 360 and 400. The ONLY time Ive ever seen a 318-sized BBD on a BB was in a '60-something D-500 tow truck with a 413, and it used an adapter (spacer) that was at least 3" tall... the manifold was drilled the same as teh carb, it wasn't like it was adapting from big to small pattern. IIRC, I remember reading something along the lines that a small 2 bbl on a bigger motor would bring out more torque.

I have a BBD on a Super 6 maifold with stock exhaust manifold and 2.25 pipe. This is on a fresh motor with a Comp 264 cam and big valve reworked head. The motor is of course limited by the carb and exhaust,,,but not as much as you might think. I would rather have this combo than say a 4 barrel with no cam and headwork.
The smallish carb keeps the manifold vacuum high and the motor very responsive and tractible. It also gives a pretty good carb shriek with an open element air cleaner. I dont hanker for more carb.... Now Dutras might be the next step.....
IIRC Dennis ran a BBD for a long time with quite a cam.

I could see 15s with a BBD...if all else was hapnin.

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Yeah....Im the one who destroyed this rare, vintage automobile.....