My 280C has a Solex 4A1 4Bbl, and as far as I know, that's what all the 110 carbureted engines came with from the factory. They are a troublesome carburetor to maintain, and could have been replaced by the Holley on your vehicle. The 4A1 works real well on our car, but the mileage isn't very good - I blame the overall gear ratio more than the engine or carburetor for that. You must remember that when these cars were designed, fuel consumption was not an issue. The 4.3L V6 I put in my 300TD produces almost 1 1/2 times the mileage in town and twice the mileage on the freeway because it's got a better gear ratio and the fuel management is very precise. The 280E's used fuel injection, but it would be a big job to retrofit to your engine. (You'd probably have to replace the head) If I were you, I'd try to tune the setup you have so it works well. You might try replacing the differential with one that has a better ratio if you are interested in mileage.

Richard Wooldridge