I was planning on adding a greddy turbo kit, just for piece of mind would it help to add a block guard and thicker head gasket???

the greddy kit comes with an 18g turbo right? Once my block gets built and I turn up the wick a little more the 18g is capable of higherthen greddy stock boost levlels right? I know a WRX wi an 18g upgrade who is pushing 370 to the wheels on an 18g at 22 or 24 psi One or the other

 

You'd probably want to run forged internals to be able to handle that much boost reliably. H22 ringlands aren't the best when it comes to boost.

But in order to run forged pistons, you'll need to resleeve. Hope you have $$$.

Which H22 do you have? JDM, a1, or a4?