Compared to a classic C-130 a new propulsion system…, has four (the HC/MC-130J has 8!!) multi-functional head-down LCD displays which are night vision goggles compatible. Two mission computers and two backup bus interface units (inaccurate - BIU’s are used continuously for normal operations and there are no backup BIUs. There is a operational state called BIU backup if we dual mission computer failure) provide dual redundancy. In the baseline (airlifter) version the avionics upgrades result in reduction of crew to 2 pilots and 1 loadmaster - no flight engineer, navigator or radio operator is needed in the cockpit anymore. (HC/MC-130J has a CSO)
The extensive modifications also feature a belly-mounted 360-degree surface search radar (NOT on the Air Force HC-130J), Direction Finder system, nose-mounted electro-optical/infrared (this isn’t a radar) radar, FLIR (redundant and inaccurate since our EO/IR system isn’t just forward looking, an airborne Automatic Identification System and new communication systems.
The HC-130J furthermore offers external fuel tanks, flare/smoke float launch tubes (NOT on the AF HC-130J) and the USAF-standard liquid oxygen system has been converted to gaseous O2. (You obviously got this one confused with the Coast Guard HC-130J.