Can I use the intel stock heatsink from a Kaby Lake i5 on a i7 7700k?

[quarfx]

I'm not overclocking, are there any concerns with using that heatsink?

 

[chemmajorp53]

you can but it might get pretty hot, as in uncomfortably hot even under just gaming loads

 

[Danra]

Intel does not supply a heat sink with the i7 7700K for two reasons:
1.) They want to get as much money as they can.
2.) They do not know what case you are using.

You will overheat the i7 7700K if you use a cooler from an i5, the i7 7700K gets hot.

You should at least purchase a moderate air cooler. ARCTIC COOLING Freezer i32 120mm Fluid Dynamic CPU Cooler. You can get it at various places, here is Newegg https://www.newegg.com/Product/Product.aspx?Item=9SIA4RE4M24012&cm_re=Arctic_Freezer_i32_Cooler-_-35-186-140-_-Product

This cooler comes in two versions, this one is $4 more. The difference is this one has a fluid bearing and will last much longer than the less expensive version. http://www.tomshardware.com/reviews/arctic-freezer-i32-cooler,5004.html

Personally, I like the Noctua NH-U12S much better, however, it is more expensive.

Make sure any cooler will fit inside your case, use a ruler to measure from your motherboard to the inside edge of your case, minus the thickness of the CPU, about 6mm.