Search:

This is starting to sound more loke the valve clearances were set to tight. If you had a hole in the piston the engine would be pumping smoke out the exhaust and breathers, but you have not mentioned...

Spin the motor by hand first and see if your pushrods go up and down. Could be your cam has dropped a lobe or a collapseed lifter. If not then pull the head. Then you might find a blown head gasket,...

Another area to check is your balast resistor or resister wire, when cold voltage shouild be 12. 3 volts and when warm voltage from resistor to coil should be 9.4 volts.