I like the Zenith on my 248; no horsepower to speak of, but you can't find a flatter torque curve. I don't know if the Zenith downdraft was standard on the 270, but I believe the updraft carbs were used on COE and big rigs only... :confused: I'm sure someone will jump on this with a correction. :p

1955 First Series GMC 250 1-Ton Panel
In the Gallery
Mr. Hedgehog - Follow the build
If you can't laugh at yourself, I'll laugh at you.