No.

5970, although a good card with dual GPUs, awesome for gaming, SUCK ASS for mining.

You cannot crack MSI Afterburner using them.  Which means you cannot underclock the memory or overclock the core very much.

You are better off getting two 5850s and over clocking the HELL out of those.  That is basically what a 5970 is.  Two 5850s but I would rather have two 5850s ANY DAY over 1 5970.