I got a response from Antec:
Comment: Dear Greg,
Thank you for contacting Antec Customer Support.
First of all, sweet system you have there!
Looking at all your specs and that you are overclocking as well, your power demand is reaching almost the limit of the 750W PSU. Since our power supply units are continous power and the model you have can deliver that amount of power you are still ok. I would suggest to look into getting a stronger unit maybe in the future. The HCP 1000 PLATINUM is a great choice for your system.
Regarding the adaptors you should not have problems. The additional lines on the 6+2 connectors are not used to transfer power anyways, but are there for controlling and monitoring the power demand.
If all is well and working fine, you have nothing to worry about.
This support ticket will remain open. If it should get closed by the system without a solution found, please send an email to [email protected] mentioning the Ticket ID in the subject.
Best regards,
Antec Customer Support