Please help with OIL in 250 cooling system

[Matt58]

Hi guys I have a 66 c10 with the original 250 and 3speed. It needed an exhaust gasket and the manifold resurfaced. To get the exhaust off, I had to remove a bracket (old aftermarket A/C) that was held on by the front two head bolts on the driver side. I removed it and replaced the bolts. Got it all back together and running but now have oil in the radiator. I removed the valve cover and made sure all bolts torqued to spec, flushed out the radiator, heater, and head. Got it goin again but still have oil in the coolant. Did I wreck the head gasket ? or worse? Would it take a while to get all the oil out of the system even though I ran a lot of water through it? I left the radiator cap off and when the thermostat opened it was like chocolate milk again. Sorry so long but please help. Matt…. Also no water in crankcase, only oil in cooling system