I am going to toss this out there: there has been talk off and on for the last few years about a thing someone calls "Blackhawk +" which would include a transmission that can handle more than the current one. Mech, have you heard of this?
While ITEP addressed engine improvements, there was a program involving both Bell and Sikorsky to do much the same thing for the transmissions, which was the FARDS Program (Future Advanced Rotorcraft Drive System) and looked at ways to improve the drive system power-to-weight ratio, reduce production, operating and support costs, lower noise etc, and automatically detect critical failures.
I believe Sikorsky were looking to fit it to the current fleet of 60’s, as well as an option for the FVL Program, but in spite of lots of findings, I have not seen any news for a few years now.
Thinking ITEP and if you know the S-76B and S-76D at all, you will know only too well the resulting airframe structural problems and modifications required, as a result of installing lots more engine power, so I’d be interested to know what Sikorsky has done to the ITEP 60M demo platform currently undergoing ground tests, in order to cope with all the extra power?