Need a little smog help with my new bronco. Its a 79 with the 400, trying to figure out what smog parts I need. I am in CA, but the truck is originally from Arizona. Any help would be great.

 

Thermactor fresh air is plumbed to the cylinder heads where it is introduced just downstream of the exhaust valves. If your truck has a catalytic converter, it is also introduced into the OEM cat upstream of it. CA-equipped trucks were usually slightly different in the emissions configuration. Your best bet is to seek out the vacuum and thermactor plumbing diagrams for the truck. Chilton's often has this information in their manuals than Haynes but ideally a Ford manual would be helpful. It is also quite likely someone actually has more info than I can offer.

 

A new user just posted this photo of an 87 Thermactor air diverter valve (broken) in this thread that confirmed something I wasn't able to recall. Thermactor air injection and the plumbing to it includes this diverter as far back as the earliest EFI models and may have been present in late model carburated units as well.