Dual channel overclock 1333 to 1600 and run with 1600 pair

[danbennett123]

Odd title i know but i'm hoping someone may be able answer this question. Basically i currently have 4gb of ddr3 1333mhz which i can easily clock to run at 1600mhz. I have 8gb of 1600mhz vengeance on the way and was thinking if the 1333 were paired and clocked to 1600mhz then could i run the whole lot at 1600mhz if i could match the timings maybe 9-9-9-27 or something similar. Im aware that if i just add the vengeance then the whole lot will run at 1333mhz without the oc.

Thanks in advance
Dan