You definitely can flash the ghz bios to a regular 7970, just google it. Idk the success rate though.
Tomshardware was unable to do the flash process. however, it doesn't even need flashing the BIOS all you need to do is just an OC.
Clearly, something's not right. Just look at the memory capacity. Then there's the GPU clock rate and missing support for OpenCL/DirectCompute. In the end, we’re forced to concede that upgrading an old board to the new BIOS just isn't as easy as it was in the past