Well when i start my iroc up and let it idle for aboue 15-20 minutes it will start to hit 220-230 area before the carb swap it never got passed 180. It has a 180 t-stat just like the fi did. The radiator and water pump are the same and only a couple months old. The only difference is it no long has a cts sensor and only one fan runs instead of two. Is not having both fans running cause it to head up that much more?