Me again, I've got an important question. I've got a 78 cheyanne with AC, 350, 1/2ton, etc... I noticed in the spec page that in 77 or so they all started coming with catalytic converters. Is this 100% or did they have canadian models or any without. The sticker under the hood is gone and it doesn't have cats. Was wondering if it ever did. What other emissions did it have? air pump? egr? ETC? Mine has none of this and it doesn't look like it ever did. Manifolds dont have AIR connections ( maybe none did) Cats are easily put on but finding other stuff (if I need it) can be a little hastle.... Blood, sweat, tears, and lots of money is what keeps my K5 alive.