If you're speaking of the Holley 2300 two barrel it is definitely not a good MPG carburetor. In fact it can be worse than a 4 barrel because the 2300 is basically a 4-barrel with no primaries. It is a good carb for circle track racing where you can only run a 2-barrel, or for the end carbs in tr-power setups, but waht TioNeldo55 is talking about is the Holley-Weber staged 2 barrel, with a primary and secondary venturi. They are around $65 rebuilt from
Stovebolt - adapter, linkage and air cleaner are extra.
