4670 crossfire

hi all ive got aasus ati 4670 which is pretty good but im after a bit more power if i get another 1 will i get a reasonable more power for gaming out of the 2 4670s thanks if any replies

and would i be able to overclock each 1 to 800mhz instead of them being 750mhz

Crossfiring such weak cards isa very bad idea- you would get a much bigger performance boost from selling your current 4670 and buying a 4850.

4850>>2x4670