[keithss]

I may have made a big mistake. I have a 70 "396" that I put the correct chrome valve covers on. I blocked the "breather" line going to the air cleaner since it did not have a connector. After running for awhile, I began smoking from both banks and also see some oil blowing out the rear bottom of motor. Am I screwed ?

[steve70malibu]

It probably blew oil into the pcv valve which will go through the carb and make it smoke, the oil leak sounds like the pressure pushed oil out some gaskets. Just clean out the pcv line and valve then clean the engine. Unplug the breather then try running it again and see if it clears up.