hello my 71 240z runs hot everytime i sit for a red light it shoots way up there almost to 250( red line on gauge) now even when i drive and am moving it run hotter than i feel comforable with unless its cool out like in the 70's then its ok...ive done everything ive read on this site to fix the problem : new thermostate. new hoses. new waterpump, belts adjusted .flushed the heck out of the system (entire system not just the rad, and new fluid...so....i guess its time to replace the rad..want one that will cool better than stock..any ideas?? ive heard summit has one but cant find it in the catalogue...im in Florida and it gets real hot in summer to the point i really cant drive the 240 then...any ideas or help ???thankyou michele