ish... the factory service manual says 170* (99.99% positive) when driving your car hard or after running on the freeway and letting your car sit for about 5 min. temperatures w/ a stock radiator can hit a little over 200*F (~93*C) w/ an upgraded radiator like you have and stock thermostat temperatures should remain ABOUT 180-195F (~82-90*C) under the same conditions. (this is off the top of my head after the research I did on this site about 1 yr ago. I have the HOWE radiator w/ the stock thermostat!. Nismo t-stat I BELIEVE is about 160F but I'm not sure.
"Be kind, for everyone you meet is fighting a harder battle" ~ Plato