[dsraven]

maybe just get another set of valve covers from a '70's era engine and install the breather filter and pcv valve from that size of engine. the pvc is calibrated for the cubic displacement and then there may be one available for high mileage engines which would have more blow by. if that doesn't cure it then do the compression test, cyl leakdown test and go from there. maybe the engine guy broke a ring upon installing the pistons or maybe the rebuild was a can of paint. rebuilt means a lot of different things to different people.