no oil to top of head

:confused: :banghead: My dad bought me a truck a 1983 c10 with a 305 looks real nice and runs real good but I get little to no oil to top of head. I have already changed oil pump and rear main seal to fix all leaks. I have also flushed motor 3 times. What else could be wrong? My dad said it sat for a year or two but was started every so often. He paid $2000 for it and Im starting to think he was taken for a ride but I love the truck. I heard the push rods could be clogged up. Can anyone out there help me? email [email protected] please!:crying:

Welcome to AF. Do you have oil pressure are the lifters noisey? Is the inside/top of the engine sludged up?