I have a 90 gt and it likes to run a little hot..It has a black magic electric fan that is wired to run all the time (new), and a heavy duty three core radiator (bigger than stock and new), all hoses and everything new, 180* tstat (new), and a brand new stock water pump..I have noticed that the heater only blows luke warm air so I am suspecting something is up with the heater core..Could there be some sort of blockage in the heater core that is causing it to do this?? Another thing making me suspicious is when I bought the car last year the previous owner had the hoses hooked up to bypass the heater core..What do you guys think?