2000 Ford Excursion Oil in the radiator

Hello,
I have a 2000 ford excursion with the 5.4l engine and I have oil in the radiator. The overflow is full of oil, I checked to see if the oil had coolant in it but found none. It also has a crack in the intake manifold, which was easy to diagnose but I can't figure out where the oil in the radiator is coming from. Every internet search that I have tried has come up with one of two causes. 1. Oil/transmission lines running through the radiator (I checked, no lines run through the radiator) 2. Blown/leaking head gasket. Any help would be appreciated. I own 3 fords, all with 5.4l engines and this problem is in 2 out of the three.