1bbl to 2bbl carb conversion

[ThatOneBlue67]

Ok, my 250 has the stock Rochester Type B 1 barrel carburetor. (Just in case you've never seen one.)



I have found what I believe to be all the parts necessary to complete this conversion. The adapter was only 15 bucks off of TD performance and this particular one fits most 2 barrel carburetors. The diagram showed that a Rochester 2 barrel would, so that one I chose to pursue. The original 1 bbl has 2 studs (as the base of the adapter has 2 holes) and a 2bbl rochester has 4 holes (and the adapter top has 4 holes as well as a rectangle setting). As for the holes that the fuel actually travels through, the large 2bbl oval tapers into the 1 barrel circle.



Before assuming that a used Rochester 2bbl would fit right on, I happened along a spacer that was hiding under the hood of an ElCamino along with a fairly complete Rochester 2bbl.



Unfortunately my adapter won't be here until tomorrow. However, once comparing the spacer v.s. the adapter, I will know. I believe that it will work, I'm pretty confident of it. Instead of blowing 2oo bucks on a new one, I'm just gonna rebuild that ElCamino one and end up spending 50 bucks. If this setup works really good, I'll probably invest in a professionally rebuilt one (or new if available). Here's what a Rochester 2bbl looks like...



I will update on Thursday (possibly late Wednesday) with the results.

[shelby987]

good luck, let me know how it works out, I would be really interested to see if it helps mpg at all.
Also, I see you have changed your sig. to read cherry bomb's from flowmaster series 40, any specific reason?
Does the linkage for a 1bbl directly swap for a 2bbl?

[JAKES 68GMC]

Good luck and have fun. I'm a little curious about what you'll gain for performance.

[ThatOneBlue67]

Well,

The adapter came today and looking at it close, I'm confdient that the used Rochester will work. I'll be visiting my friends at the treasure yard tomorrow

Shelby,

The beautiful thing about this adapter is that I can mount the new carburetor in four different positions and face the throttle set up on the side of the carburetor to whichever direction I need. Essentially, the most I would have to do is lengthen the linkage rod. I will eventually build a custom plate that has kickdown bracket built in, since I'm having such great luck finding a STOCK one!!!!!!!

And yes, I did change the sig to Cherrybombs. I decided that if you're engine can't produce a cool sound, Flowmasters are cheating. And I'm not ready to spend that much (yes, MORE frugalnesss!!!!). Besides, cherrybombs are classic and short ones could end up producing a loud, rough sound which is just bout what I'm looking for. When i go to have the exhaust rebuilt, I'm simply gonna tell them I want it loud but legal and especially cheap. They'll know what to do, that's how they get paid.

That reminds me, I ought to collect actual figures. Guess today or tomorrow is the best time. Best start looking for the stop watch....

Well, I'll update you guys! I'm gonna go flip threough my new resotartion guide, whcih I got for FREE.

[67stepsideC10]

Ever make progress on this?

[ole dollor]

i also would like to see how this turned out...

[pritch]

I'd sure take that Model B off your hands, I need some parts off it!

[geezer#99]

Gentlemen!!
If you check you'll see that the last time the OP was on here it was over 6 years ago.

[yuccales]

Originally Posted by geezer#99

Gentlemen!!
If you check you'll see that the last time the OP was on here it was over 6 years ago.

Might just be taking his time. I never like to rush a project.

[67stepsideC10]

Originally Posted by geezer#99

Gentlemen!!
If you check you'll see that the last time the OP was on here it was over 6 years ago.

4 years.
Last Activity: 09-29-2008 10:33 PM

I did figure as much, but thought maybe someone else would see the thread and comment. It's a topic I'm interested in and can't find any active threads on it.

Thanks.

[Dano69c10]

I used one of those adapters when I went from 1bbl to a 2bbl Weber.

[ole dollor]

i am in no hurry....would still like to know how it turned out.....

[ol_skool_chevy]

i tryed that SAME set up once................No change

it really was just to try it...turn out to be a waste of time

[PanelDeland]

On a Chevy 6,you will not see much gain other than maybe ease of finding rebuild parts for the components.The heads flow like molasses and this set up simply adds a barrell to the carb withot opening up the intake for more flow.The siamesed intake ports on a 6 slow down the intake velocity and more fuel will probably just pool in the itake runners.