Stock intake manifold?

[ReactionDT]

I have a 1986 Chevrolet C10 Silverado that's a 305 that was said by the previous owner to be professionally built. I know that it has a different cam, carb, roller rockers, heads, and breather but I can't figure out if it has a stock intake manifold or not. Does anyone have a picture of one or can tell me what to look for? I've looked for manufacturers on the intake but all I see is the firing order facing the front end. Thanks for any help!

[slammed79]

Try putting a magnet on it. I haven't seen a iron aftermarket intake before, must are aluminum so that's be the tell for me. I can't recall seeing the firing order stamped on a aftermarket either. Chances are your manifold is stock.