Marine aviation has been quietly getting some upgrades to several of it's helicopter platforms and while many questioned why they decided not to go a similar route the Army, AF and Navy went with their attack and utility helo's, i.e the Apache for attack and Blackhawk/Seahawk for utility, it looks like the Marines have still ended up with very capable and similar airframes to operate in their unique mission of projecting power from the sea.
Back in my day we flew the AH-1J Cobra and the UH-1N Huey and we operated in separate squadrons.
The Cobra was upgraded after my time to the AH-!W Super Cobra but the AH-1N stayed pretty constant to it's earlier upgrade.
The separate squadrons HMA's and HML's were combined into single HMLA squadrons as both tactics and logistics changed.
Now the new variants of the venerable old Cobra and Huey are being deployed and their upgrades are so extensive that they even carry new names.
The AH-1W (whiskey) Super Cobra is now the AH-1Z Viper and the UH-1N Huey is now the UH-1Y Venom.
Their capabilities put them on par with the other services helo's and more importantly their serviceability was improved with their commonality of major parts.
exp:
The goal of the USMC H-1 Upgrades Program is to achieve a platform that meets the growing needs of the Marine Corps. The 4BW and 4BN will be an upgraded version of the current AH-1W and UH-1N Helicopters. The 4BW and 4BN will share a common engine, Auxiliary Power Unit, four-bladed main and tail rotor system, transmission, drive train, and tail boom. The purpose of these modifications is to achieve commonality in both aircraft, thereby reducing logistical support, maintenance workload, and training requirements. The replacement of the two bladed rotor system with a common four bladed rotor system will achieve improved performance, reliability, and maintainability. The addition of an infrared suppresser to the aircraft will improve survivability. The 4BW will also include a newly developed cockpit, which will result in nearly identical front and rear cockpits that simplify operator and maintainer training and maintenance.
Back when I was with HMA 369 we were flying the AH-1J's and our CO at the time Maj Hugh Mitchell wanted us maintainers to get in some seat time too, even got in a little live fire (off the record of course). Spread the love if you will. Those Cobra's were pretty bad azzed back in the day and I can only imagine how more effective they are now.
UH-1Y Venom AH-1Z Viper 
