Here's the McDonnell Douglas/Vectron F-4SL Sea Phantom 2000, a heavily upgraded version of the F-4S used by the private military corporation Seawolf Ltd.
Upgrades include: expanded ordnance capability, more reliable, efficient, and powerful turbofans (with cartridge start capability) replacing older turbojets, upgraded avionics (upgraded AN/AWG-10D radar/fire control set), updated cockpit (Head-Up Display, Head Down Displays, Data Entry panel, Data Transfer Unit, HOTAS), updated ECM suite (AN/ALR-67 RWR, 4x AN/ALE-39 CMDs), Precision Strike capability, MIL-STD-1553 databus, Litton Laser Ring Gyro INS, digital mission computers, etc.
A total of 30 former F-4S Phantom IIs were upgraded under the Sea Phantom 2000 program, starting in 1985. Interestingly, due the systems being made easier to use (along with changes/additions to the front cockpit), the Sea Phantom 2000 can be flown effectively by just the pilot during interception/aerial superiority missions. During air-to-ground or air-to-sea missions, a backseater is preferred for splitting the workload (as well as actually using any sort of targeting pod).
The new turbofans, those being Vectron-built F130-V-100As, provide 20,670 pounds of thrust in full afterburner. This gives the Sea Phantom 2000 a combat thrust to weight ratio ~1/1.
(I hope y'all like this one! I still have yet to work out the cockpit re-design, but I do have all the resources required. Anyway, I'm sure y'all can guess that this one's based on mixing the F-4S with either the Boeing Enhanced Phantom or IAI Super Phantom. Been wanting to develop a "modernized" F-4S for my Stratos Ultima worldbuilding project for awhile now, seeing as the main corpo I'm working on developing currently [Seawolf LTD] is like a privatized US Navy/Marine Corps, including their use of an Enterprise Class aircraft carrier, possibly a smaller refit Essex Class, and multiple Amphibious Assault Ships. Small but funny story, I had actually asked
@heatloss1986 to help me out with technical stuff, including inquiring if a Jet Fuel Starter could be shoved in there somewhere lol. Of course, no dice, so that's why it uses hydrazine cartridges for self-starting.)