I used to have some references for this but can't find them. From memory the big items include the enhance glass cockpit with bigger displays, conformal fuel tanks, a centreline enclosed weapons pod for better RCS, some minor geometry changes for a small RCS reduction, IRST, and enhanced engines. I can't recall if there is a planned radar upgrade above and beyond what the SH already has. All together, these enhancements defined the ASH (advanced super hornet). Most of these items already exist (some available now for existing SHs) with the exception of the new engines. One plan was running the existing F414s at full military power for better performance but less durability. Needless to say the USN was not impressed. Not sure about other enhance engine options.
The bottom line is all this stuff improves the SH but it still is far shy of being a 5th fighter ( no sensor fusion, no advanced networking, etc.) and the overall cost will start to rival the FA-35's cost. Canada has already been sucked into this short term solution and we will pay big time for this mistake (likely won't even include some of the above new features.). Hopefully the USN won't follow this path.
