"When the F/A-22A Raptor became operational, the Israeli Air Force was one of the first to ask for the new fighter to be exported, but it was a short-lived dream because the US government deemed the aircraft off limits for exportation. It was to be an American fighter only as the technology was top secret and there was no way the USAF would allow their best aircraft to be used by anyone else.
In early 2015, the IAF sends the US government, an order of 25 F-15SE airframes to equip 2 squadrons, surprising everyone, including Lockheed Martin.
The debate among IAF generals, about the purchase of more F-35s was heating up because of the supposed lack of maneuverability in a dogfight, this being a critical issue for the IAF, which, by having such a reputation of aerial combat masters, didn't wanna rely on the alleged ability to survive by having a higher situational awareness and better electronic countermeasures and stealth.
The IAF Generals wanted to have 2 squadrons of new F-15 fighters to replace the aging models, which are now well over 20 years old and all have a large number of flight hours. Also, there was a growing concern that the sovereignty of the Israeli state was becoming compromised with their neighbors' latest military acquisitions, so the air superiority would have to be a priority.
From when the order was submitted to the US, the new fighters, which were to be F-15SEs, but the IAF wanted single seat Silent Eagles, but Boeing wasn't very interested in reopening the single seat assembly line for only 25 airframes. They were "forced" to take the twin seat SE, which were to be equipped with indigenous hardware made by Elbit systems.
While the US congress decided if the sale would be allowed or not, the IAF generals asked Elbit engineers if they could use the Silent Eagles as an example to convert the old F-15C BAAZ/2000 airframes into Silent Eagles. "Yes and we can make it better than the original ones!" they said.
The generals scratched their heads but gave them the green light, for them, if it flew as good as the F-15C and had up-to-date avionics, it was fine.
The engineers at Elbit would only have to wait for the sale to be accepted. In a couple of months, the first 4 jets arrive at the Elbit hangars for the electronic systems installation. At the same time, the engineers made sure they got every bit of info they needed to convert the old airframes into "almost 5th gen" fighters...
Along with structural reinforcements, there would be a few new features used on the Eagle for the first time, like the internally-mounted IFTS sensor in front of the canopy, 2 powerful radar jammer pods on the wingtips, similar to the ones on the EF-18G Growler. This would make the Eagle much harder to detect when engaging aerial opponents, as it could reduce detection range by over 40% on enemy radar.
But the most striking external differences would be the SE 15º canted vertical stabs, and the new intakes, which were redesigned and reconfigured with radar wave deflecting panels on the inside to hide the engines, with the leading edge angles aligned with the LE of the wings.
These new F-15s would be covered with a coat of a special formula of paint, supposedly created by Elbit systems. Although there were rumours that Israeli Mossad spies had infiltrated the Lockheed Martin's Forth Worth facilities and stolen the F-22 and 35's paint formulas, the Israeli government would deny these accusations and point fingers at the Chinese.
Even if it was derived from the stolen formulas, this coating was developed to be stronger, strong enough to resist the scorching heat of the desert and sand storms, and yet maintain it's radar absorbing properties for a reasonable period of time.
Redesignated by the IAF as the F-15CSE "בז שותק" or Skia Baz, the Shadow Falcon, these new fighters would be stationed with the 253rd squadron, the Negev, at Ramon air base, from the beginning of March, 2017. Joining the F-16I, this would become one of the best equipped squadrons, protecting the southwest region of the country."
List of important internal upgrades:
FAST packs, which held 4 amraams, carrying 2000 pounds of fuel, a new AESA radar similar to the Raytheon AN/APG-82(V)1 but with optimized air to air modes, new communications and data link system capable of integration with the future F-35I's MADL data link, electronic jammer pods with MILDS sensors, EADS sensors just below the cockpit canopy , the newly developed EL-100 IFTS sensor, with capabilities similar to the Pirate IRST of the Eurofighter Typhoon, placed in front of the canopy.
Python5 and the new I-Derby ER missiles with reduced front fins to fit into the missile bays on the FAST packs would make this a frightening adversary for quite a few more years."
Thanks, Nigel! 
