1964 Falcon Futura two door sedan.

[Beechy]

Yeah Paul....the propane install seems weird to you guys but it's readily available in gas stations here as most taxis and a lot of contractors' pickup trucks use it.
Both my cars have been built as daily drivers, the Camaro has 100,000 propane miles on it despite being in storage for seven years while we were in Bay Area.
Because I started from scratch with both engine builds, I've optimised cam profile and ignition timing to suit propane. Timing needs to come in earlier than normal.
I paid $600 for new tank and used mixer vs $1700 here for EFI carb.
Camaro gets 28 mpg (equivalent) suburban driving. It burns clean because its already gas and doesn't condense on intake runners nor cylinder walls, so doesn't contaminate oil (oil stays clear and clean indefinitely, but needs changing eventually because it always loses it's additive package).
Emissions are tiny amount of CO2 and a drop of water. I'm waiting for the day that I can park at the front door of the mall in the ALTERNATIVE FUEL spaces.
I didn't have a gas tank with either of my builds so buying a propane tank was a wash. Camaro has forty gallon capacity in two stainless tanks consuming the entire trunk space but for a space saver spare. Needless to say the fabrication/welding on a stainless tank is an art form. X-rayed pressure vessel.
I have air/fuel ratio gauge in both cars so I can tweak mixture occasionally, so nearly as good as fuel injection in that respect.

BESIDES, GASOLINE DON'T SMELL ALL THAT GOOD EITHER!