your pcv valve or hose is restricted causing excessive crankcase pressure
The 390 Ford motor is an FE block and was made as a Big Block only. The small block or Windsor motor could be bored and stroked to have 390+ cubic inches. To build a stroker motor you have to do extensive machine work and parts matching. That process usually involves large amounts of money.
It is on the back of the block, next to the distributor.
on the back of the block on top of the bellhousing mount
On the driver side of the engine behind the fuel filter on the side of the block
Near where the oil filter mates with the block and there is a port on the top of the block just behind the intake near the distributor.
One possible cause is a blocked PCV (positive crankcase ventilation) valve. As your motor is running the crankcase will build with pressure and the PCV system will let the motor breathe. If the PCV valve is blocked or faulty then the motor will look to release the pressure somewhere else.
It is located on top, at the back of the motor near the distributor. It is screwed into the block vertically.
Passenger side of the engine block, to the rear of the motor mount.
a block is not a kind of motor, is is a piece of a motor. it is the part that the piston moves up and down in.
The oil pressure sending unit is on the back of the block just above the bell housing. The unit screws in.
Back of the engine block, next to the distributor.
top of block pass side under edge of intake at front of motor