Welcome!
Beautiful Fury you have there.
Personally, I would not upgrade to a 4bbl as this is a classic cruiser unless you plan to do burn outs and strip racing with it.
This will be decent of fuel economy and if you start messing with it you could end up with a whole world of fuel related issues and end up wishing you hadn't touched it.
Having owned a previous C body I'm sure you know all about the great electrical systems we have been blessed with.
If you are looking for things to do, I would recommend that you check & clean all electrical connections in the car as Mopar is known for having electrical challenges especially with the amp gauge and firewall block.
Here is a link to how to improve the charging circuit.
Mopar Charging System - MyMopar.com (Don't install a too high amp output alternator if you need a new one in the future. (The electrical circuit can't handle it.)
Replace the voltage regulator for the gauges with an electronic one. This will stabilize the gauge package if the needles happen to pulse while running.
The headlight switch is another area that should be looked at.
Another great electrical upgrade to do is to install relays for the headlight system and by-pass the loads on the headlight switch and dimmer switch.
Daniel Stern Lighting Consultancy and Supply
There are kits you can install or if you are good with electrical wiring can make your own.
Here is a few links to the Mopar manuals and parts books as well.
MyMopar - Mopar Forums & Information - Parts & Accessories Books
MyMopar - Mopar Forums & Information - Service Manuals
Anyway's hope you have a great time with this convertible, as we all see it is a great ride you have there.
Nice car!
