Rebuilt ford 302 stroker with 8000 miles why does it blow oil out into the air cleaner box and out the tailpipe you put a new Pcv valve in and ther was no change?

internal crankcase pressure is forcing oil through the PCV valve into the air cleaner.

first thing to check is for vacuum where the PCV plugs into the valve cover. you can use your hand to cover the opening or use a vacuum gauge with the car at idle (vacuum should be 3-5)

If you have pressure instead of vacuum the next step is to the other valve cover. it should have a hose coming from it that goes to the base of the carb or vacuum port near the plenum of the intake manifold and check for vacuum. this is to pull all the crankcase gasses into the intake and burn it in the combustion chamber and out the exhaust. the side with the PCV valve should be pulling fresh air from the airbox