Its made by Rochester, has older style choke for use with a rod, and a side exit fuel line. Numbers are: 17057213AWP and under it, 2546.
Thanks!

According to the interchange..

1 of 5 different carbs used on 1977 Blazer and Jimmy, 350 MT and 400 engines with federal emissions meaning not on any CA vehicles.

Rochester M4MC

AWP is the broadcast code (assembly plant use)

2546 I beleive is the Julian date, 254th day of 1976

Thanks!