You have a Rochester carburetor on a USA 1954 350 248/270/302 GMC engine?
It looks like that was a Chevrolet 216 engine carburetor (7003863)?
Is that correct/original, Spanky?
GarlandFarms: use the carburetor tag-code for parts (do not try to find the right parts by using the GMC truck-size/engine-size).