More hp need more cooling
 

I bought a 1999, 4900 International with a dt466e 19th . When I bought it I knew it needed injectors. So I had my mechanic put larger injectors in and turn up the fuel. I am now around 240 hp. Of course the dad doesn't work. Problem with the dash is not in the dash like most of these trucks. I noticed overflow tank kept spilling over so I bought an OLD gauge and the truck is running over 220 Dec. So unfortunately I do not have history before turning up the engine. I took the thermostat out, tried running radiator cleaner. Antifreeze looks clean. Coolant is sloshing around in overflow tank so I think the water pump is working properly. Fan is working properly and the fins on the radiator are good. I have a half radiator. I have contacted international dealers and radiator suppliers and I have not gotten my questions answered. They are: What size radiator came in a truck with 250+ go. Will a full size radiator and air cooler fit in my truck if so what modifications would I have to do and which radiator and air cooler do I need. Do any of yal know these answers and do you believe this is my problem or should I look at something else. We have been driving the truck very easy and the weather has gotten cooler. The engine temp had dropped but still over 200. Truck has 4:44 gear with 6 plus1 transmission. I have thought of lowering gear to take strain off engine but I don't think that's the constant overheating problem.