The K series processors are for overclocking, the non-K variety.... not so much so.
All K series processors come with an unlocked multiplier, to overclock a K series, you simply increase the CPU multiplier till you reach a point where you're happy, or cannot go any further. If the latter happens first, then you can start getting into the nuts & bolts of overclocking, playing around with voltages, improving your CPU cooling performance, etc...
With the 4690 non-K variety, any overclocking will be strictly limited to Front Side Bus overclocking. It comes with a locked multiplier of 35x and FSB of 100MHz for a stock frequency of 3.5GHz. This can be beneficial to a degree, because the memory controller cannot utilize memory speeds that are faster than it's designed to handled, but FSB overclocking overclocks everything within the CPU, the core, the cache, the IGPU, the memory controller as well. If for example, you had high-end RAM, say DDR3-2133, then you could set the RAM in BIOS as DDR3-1600, & with the RAM tied to FSB, as you increase the FSB speed, you're also increasing the RAM speed, as well as the memory controller speed all on a 1:1 basis.
So, if for example, you increase the FSB to 115MHz, your CPU speed then goes up to 4.025GHz, and your RAM speed increases to DDR3-1833 (1840 technically), and the memory controller is now running at a maximum 1833 speed. Push it further till you reach DDR3-2133 speed on the RAM - 133MHz FSB (technically to reach DDR3-2133, FSB would need to be 133.33MHz) & your CPU is now at 4.65GHz. Unfortunately, this is only of real benefit to applications that are memory intensive. With a K series CPU, you would just need to set the multiplier at 46 or 47 to get 4.6GHz or 4.7GHz.
However, since your starting with DDR3-1600 RAM, you might need to set it to be independent of the FSB speed. Although Corsair Vengenace may overclock to around 1833 or possibly a little higher.
The biggest difference between the K & non-K overclocking top speed, is going to be the motherboard's ability to reach a relatively high FSB overclock for the non-K CPU, and that's where the K's usually win out, cause the 4690K can hit 4.7GHz with a good cooler (& theoretically so should its non-K twin), but not a lot of LGA1150 motherboards able to hit 130MHz or better on FSB as I understand it.