Got a pic of the engine bay by any chance? I've removed 3 of those smog systems from both my malibu, a 80's silverado, and an 85 dodge 150. The easy part is tracing out the rubber hoses and capping off any open ends. With the manifold, remove the EGR valve and put in a bronze cap to block off the EGR hole. You can get almost any fittings you'll need for your manifold at home depot or lowes. The hard part is concerning the exhaust manifolds. Let it be dodge or chevy, there is always some kind of tubes that run from the smog pump to the back or the sides of the exhaust manifolds. And most of the time, the fittings or bolts holding the tubes are rusted to hell and are hard to break.
Its probably gonna take a day or weekend when you can carefully trace out all the hoses and wires. It's a pain in the *ss no matter what it is. Most of my info here is based on the stock 80' 305 that was in my malibu so hopefully a 307 is similar. If not, then my bad.