409 turbo torque

[Verne_Frantz]

I really don't have a good answer for you. The original sales literature lists the engine as a Turbo Fire, and so do the original valve cover decals. I can't explain why the shop manuals refer to it as a Turbo Torque. Perhaps that name came from marine applications?
As for the Z-11, I've never seen that RPO listed in any printed Chevy available options lists. So, I don't know what name it went by. And the original Z-11s did not come with any valve cover decals.
Sorry I couldn't be of more help.