Mpg 318
What about the Carter 2bbl?
BBD's have treated me very well. ive rebuilt quite a few for friends and other people, havent had one come back yet. those damn holleys though, they have burned me more than once. ive only had one that actually ran well. one out of 6. their limited adjustability doesnt help much. ive converted everything I own(ed) to 4 barrels, thermoquads, couple 4160 holleys, and a 4175 holley, and quite honestly, i havent looked back. mileage increased, driveability was better, and cold starts are no problem. obviously theres more things that could be wrong, but with the OP stating hes running a holley 2 barrel, id question it, even if its rebuilt. air/fuel gauge or vacuum gauge, and a plug reading is where id start. (NGK GR4's, get some, you wont regret it)