What are the mining spec differences between Bitcoin and Litecoin? Obviously, Litecoin mining requires less computational power as it it more CPU friendly, but does this mean that if you switch a GPU Bitcoin miner To Litecoin mining you will be wasting your resources?
Primarily the differences between Litecoin and Bitcoin are reduced block generation time and use of scrypt in place of SHA256.

It's not the Litecoin requires less power as much as the difficulty rate is much lower due to less mining power. Bitcoins used to be mined on CPUs, but the introduction of GPU mining essentially put that to an end.