Your going to hear a lot of different opinions on this subject but as far as I understand the law here in Virginia if you do desmog the truck your breaking the law and heading for one hassle after another. If you do is as the owner of the truck it's not a huge infraction and your not likely to get punished but it's a felony for a mechanic/repair shop to do it for a customer. It's considered "tampering" and any reputable mech wont do it.
I've called the Virginia DEQ about this several times and gotten the same answer each time.
Even if the truck does not have to get a smog inspection, it's still supposed to have the smog gear to get a safety sticker (visual inspection of smog). What you can get away from one inspector to another varies widely and you'll have to deal with it every year. A header and a Weber is a dead give away vs just pulling some of the smog off but retaining the stock air cleaner and exhaust manifold....not all desmog's are the same and some are harder to get through than others.
If you get antique tags then it's a not issue but your not supposed to drive it daily. I've been hassled for this and so has my father in law.
This goes back to 1973 when smog first appeared on cruisers 9/72 and newer production date.
My good friend Josh desmogged his 79 FJ40 and never got it through safety inspection after doing it. He did not want to have an illegally obtained sticker so he sold the truck.
This is why I've owned so many 71 and 72 FJ40's as they are the newest FJ40's that did not have much of any smog aside from a PVC valve. All the rats nest of stuff started to appear in the 73 and newer trucks.
Why do you want to do desmog it? Runs badly? Send your carb to Mark Algazy or Jim C. Adjust the valves, give it a solid tune up and you might be suprised how well it can run. Compression numbers? What kind of vacuum does it pull at idle? How does the needle look? Many older FJ60's need the head rebuild as the valves get burned from vacuum leaks. I drove a 60 until my knee went out and even with all of the smog still on it it ran great after I got the motor sorted out and dialed in. My advice would be to focus on doing that vs. a desmog. Just my opinion!
I'm in Great Falls so I'm close by, I don't have time to help you work on it but I'll kick the tires on it and tell you what I think of how it runs and what you should focus on for a cup of coffee.
-Stumbaugh
PS Welcome to the CLCC!