The Carter YF that would work is the 2100S. Use caution etting them, though, as there is a ford version that is jetted WAY to rich for Chevy use. Sometimes the rebuilders don't get the right carb in the right box.
As far a Holley goes, yes, the 1904 will fit, but most of them seem to be made for a right side intake (ford, IH, GMC V6) so some modification might be necessary to make them fit a Chevy. If you get lucky, there was a lesft side version used on late '50s GMCs that would work. Rejetting is easy, as they use the same jets as the later 2 and 4 barrel Holley carbs.
