When first fire of my 410,I had a similar thing happen.I forgot the cork gasket inbetween the block and plate.Fired it up,ran great.I shut it off and climbed under the car to check for leaks and layed in a puddle of new Brad Penn oil and soaked my shoulder.LOL.I have old carpet down under my cars(for cheap insulation in the winter)so didn,t see the leaking.Thank god I have a roller cam and wasn,t doing a 20 min breakin of the cam.Could,ve been disasterous!Live and learn.:angry7: