Ram mixing question

[eevee047]

A friend of mine offered me his 16gb ram kit (2x8gb). I have a similar set of ram, both are corsair LPX. 
Current set is CMK16GX4M2A2400C16 and the new set is CMK16GX4M2B3000C15. Now, I know there's issues mixing different brands. But, can I not downclock the new kit to 2400Mhz and Up the Cas Latency to 16? 
My thinking is, they're basically the same kit, just one was binned for speed. 
Is this possible? I'd pick up a similar 2400 Kit to mine, but the kit I'm potentially buying is going to be much cheaper than I could get elsewhere since it's through a friend. 

[Crunchy Dragon]

Your board will default all RAM to the speed of the slowest stick, it doesn't particularly matter IMO.

 

Once installed, you can muck around in the BIOS with clocks and latencies as needed.

[eevee047]

What about the Cas latency though? Will it automatically change that too? 
I guess if It doesn't, I can just change it manually though. I don't see how bumping the cas latency could be an issue if the stick is downclocked.