will this compression fit this block

[spider monkey]

will a alphacool rotary 90 degree compression fitting fit a xspc raystorm cpu block

and will a xspc compression fitting with g1/4 fit a koolance r9 290x/r9 290x water cooling block

[Oshino Shinobu]

They should, yes. G1/4" is pretty much standard now, so the vast majority of fittings and blocks will work together. 

[Leonard]

They should, yes. G1/4" is pretty much standard now, so the vast majority of fittings and blocks will work together. 

For every water cooling maker but EK.

 

will a alphacool rotary 90 degree compression fitting fit a xspc raystorm cpu block

and will a xspc compression fitting with g1/4 fit a koolance r9 290x/r9 290x water cooling block

Yes but how you angle the fitting is up to you.