What do you mean by blocked off the original heater ports? You do need the LIM heater outlet connected to heater core or atleast looped back for it to flow properly.
It's normal for it to get a little bit hotter than the tstat for the reasons the previous reply stated. I wouldn't go with a 160 tstat unless the car is just setup for racing, a better idea would be to get or make a drilled 180 tstat.
86 Fiero GT 4spd - L67 swap: VS cam, GenV. Needs exhaust (ETA 9/13) Build Progress
98 GTP - Some mods
[This message has been edited by sco77 (edited 08-09-2013).]