did the 76 chevy short bed half ton come with catalytic converter from the factory or without?

I might be wrong,but I love mechanics,and every book I've ever read,or trucks I've seen from the '70's,don't come with them as o.e.,they can be put on for a price.My '86,doesn't have one either.

Greatly depends on where the truck was originally delivered. The smog laws across the US varied. In California, guarantee that it did, if it was from the midwest, more than likely not. Classic example is the Dodge Lil Red Express, Dodge got to sneak one last "musclecar" out the door, because most emissions laws did not pertain to trucks. HOWEVER, there were some that came with cats, and some that didn't. At this point in its life, it doesn't matter does it?

That truck did not come out of the factory with a catalytic converter on it....I do not believe it had any emissions other than an EGR valve. Good luck.

They came without until around 77, I had a 77 that was without and a 78 Silverado with.

comes without it

It came with it.