We're looking at a pretty simple emissions system with the International Scout. The two main things that you can focus on are ignition timing and carburetor adjustment. A smog check repair station should inspect these two things, as well as do a quick look over for disconnected, broken, and/or brittle vacuum hoses. A compression test would not hurt as well. This would tell us if the engine is able to combust fuel efficiently.
The main concern is that your International Scout does not pollute. When an engine's mechanical functionality is sound, we typically then want to make sure that timing is on point and the carburetor is adjusted as to not have the engine running lean or rich. Either of these two fuel conditions will most definitely increase HC and/or CO emissions; leading to a smog check failure.
