Qudrajet casting # for a 1984 California Truck

[mooxen33]

Hi, i have a 1984 Chevy Truck, 350, 5.7l, C20, 3/4 ton, truck, heavy duty,  California smog legal.  What would be the correct casting number on that Quadrajet for that application? I know that the first five numbers are 17084. What would the last 3 numbers range from?
 Second,  how would that Carburetor differ from a heavy duty truck to a non heavy duty truck, if at all?
Thank you.

[Cliff Ruggles]

I don't have access to that information.  Any later model 170842XX carburetor that is not computer controlled would have been a heavy duty or truck application.  I don't think Canadian car units were computer controlled in that period either.....Cliff