Long story short I need to leave my FB parked in the driveway for three months whilst I do some traveling. Anything I should do to prep the car, or am I over thinking this? Read of things such as oil fogging engine, jack stands and gas preserver but is that overkill for three months?

81 FB. Outside in driveway with car cover. California weather.

 

3 months? Nothing to worry about.
Maybe take the battery out and put it on a tender.
Extra precautions for theft like blocking it in, etc.
Everything else would be just fine.

 

If you're worried about possible theft, nothing will stop it from being stolen if they want it, but you could disconnect the fuel pump connection in the bin area to stop someone trying to drive it away.

Back in 1989, I bought a 1985 GSL-SE. It was stolen by having it towed from my apartment. This just so happened on the 30th day of ownership. And the ironic part was that I got the title that same day in the mail. They found it in Bridgeport Connecticut on the street as a bare shell. There was nothing I could have done except maybe put it in garage.

 

I would air yhe tires up a little extra and cover it. Maybe put a set of wheels chocks behind the back tires and leave the parking brake disengaged and rhe transmission in 1st gear. Other than that, as stated above discount the battery or remove it and put it on a battery tender.

 

Battery out, tires aired up to 40, car cover and sun visor, ebrake down, pull some relays and you're good. 3 months isn't long enough for anything on the chassis to "go". Gas will be fine although I suggest filling the tank and oil will be fine too.