A 1950 GMC model 100-250 used a Zenith Model 0-11147 Carburetor, GMC Part number 2194114.
The '47-'49 Zeniths were slightly different and there are over 40 individual Zenith applications for '47-'54 GMC trucks. Your profile doesn't say what model truck (1/2, 3/4, or 1 T) you have but since you said pickup, I'm guessing this is the correct one.
I think that you will find just about any Zenith will work, as will many Carters. The GMC trucks will accept a lot of variation.
I think Carter and others do offer a replacement Zenith.
