Need help with GT35R install...please!

[Riot]

New to the forum & single turbos, but looking for help on some specifics about hooking up the coolant fittings I received with my GT35R kit. The fittings I got for the CHRA coolant inlet/outlet have an o-ring & washer (see pic). Now the CHRA doesn't have a seat per say for the o-ring, but it does have a small chamfer. I am assuming that I need to use both the o-ring and washer, and the washer just helps with keeping the o-ring from squeezing out while torquing the fitting down. Am I correct?

The problem I have with this is that the o-ring doesn't really fit inside the washer, and I don't know how I would torque this down without pinching and ruining the o-ring. Also this fitting is made by Parker---and while I know they do a lot of things for hydraulics, I'm not to sure about automotive---I wonder if the o-ring supplied can even take the temperature that the CHRA will see.

Any help or advice that anyone can offer would be greatly appreciated.