I've just installed the slant six 2bbl conversion. I have a carter 2bbl sitting on the manifold now. I tried to calculate my gas millage over the past few weeks and the highest it has been is 8 mpg! A 440 gets better millage than that right? I am not driving this thing hard at all. What can I do? I can't switch to a more modern 2bbl because I don't have the money and I don't think there is any clearence under the hood. I hear people talk about metering a carburetor. What is this, how do you do it, and can it be done to a carter 2bbl? I've seen from some of the mopar parts places like The Padock, that I can buy a replacement carb. The only choices They have are for a 318 2bbl or a 383 2bbl. Plus the years differ between the two. Which carb and year would I be looking at when I get some money to replace it?
Thanks, any help would be greatly appreciated by my wallet!!

Rebuild or switch carbs, sound like the one you have is leaking raw fuel into the intake.
Holley makes a good replacement carb for the BBD

If you stick with the BBD, get one for a '71 318.

Just out of curiosity, is their a reason to use a '71 318 carb?

It will have a non-emissions caliberation and only one vacuum port for the vacuum advance. Just about any 318 BBD from before '73 could be used. There are also several other carbs that could be used in place of the BBD. Holley made a replacement, the Rochester 2GC is favored by the Jeep guys as a replacement. If you used the Rochester you would want one from a 327.