Will fit in case?

[ThunderPL]

Will fortis 3 he1425 v2 fit in aerocool pgs xpredator x1 with gigabyte z270 gaming k3?

 

[Aeacus]

Short answer: Yes.

Long answer:
SilentiumPC Fortis 3 HE1425 v2 is 158mm tall,
spcs: https://www.silentiumpc.com/en/fortis-3-he1425/

Your case supports CPU cooler height up to 158mm,
specs: http://www.aerocool.us/pgs/pgs-b/x1_black.htm

So, yes, CPU cooler does fit but the top of the heatpipes might touch the case side panel.