Something is a-miss

You dont "blow" a head gasket just sitting there. I would look at in this order Fuel system (may be fuel pump). Carb gummed from sitting (gas aint what it used to be). Also you need to know where the oil is going. How long have you had a leak? Adjust the valves after you get it running ok. I wouldnt pull it apart just yet. Do a compression test.
Just my02.
Frank