Replacing riser gaskets, which do I order. Boat is in fresh water with only raw water system. Restricted or not?

I would go with the non restricted.

Not to sound like a jerk but what in the world do you have ? Mercruiser, OMC, Volvo, Indmar, PCM, Ilmor ? And the next question what exhaust system do you have stock or aftermarket, what year model is this and serial # of your engines. It would be throwing dice as to what to throw back at you without knowing exactly what you have. Just saying. If I call the auto parts store and ask them for an exhaust gasket what would they say ? The same exact questions as I just thru at you.

1988 Mercruiser 454 mag. stock manifold and riser to thru hull exhaust