[Big hammer]

Originally Posted by 30 Closed Cab PU

You could try diagnosing just cylinder 1.


Get the rotor pointing correctly to spark plug one, Use the timing pin to find TDC cylinder 1 (rotor should still point to spark plug 1/cylinder one). If not pointing correctly, mechanical timing has slipped.


If rotor and timing pin align correctly, with the valve access cover off, use compressed air into the cylinder 1 to locate where the leak is (leak down test). You may have to drop the oil pan. If you hear air in the exhaust, exhaust valve is not seated, if you hear air in the Intake manifold/carb, the intake valve is not closed. if you hear air in the bottom end then it is possible rings, block. If the radiator cooling system is full and bubbles in the radiator or you may hear air in the radiator if radiator is not full, bad head gasket, cracked block. Not sure if I have all the symptoms/causes here.

You shouldn't need to remove the oil pan, just remove the oil fill cap! I would only use 60 lbs of compressed air.