Please help my 6.0 loosing coolant🤔
 

I have a 05 f250 crew cab 4x4 with the 6.0 motor. The truck has an egr delete,coolant filter kit,k@n intake,5"mbrp exhaust,a stc tuner with custom tunes. The truck has 202k on it but at 150k had new heads and gaskets installed. It runs at starts great when cold out the first start of day there is white/grey smoke then clears.the truck is loosing antifreeze like 1gal a week! There's none in tail pipe and no puddles under truck, there are wet spots in valley of motor on passenger side under the little blue section of hose but I never see it leak, just appears kinda wet/no standing fluid but wet? Please help I fear the worse but don't honestly know a lot about these motors. Thank u for your time.