well you could be getting oil wicking thru the intake bolts if there is no sealer on them if oil is sitting in the low parts of the intake ? if blowing out like said the breather are oil wet and if you put new valve springs in did you use the O rings or a pc valve seal if you used the o ring with out the tin shedder that sit on top of the spring this helps keep some of the oil out if you used a pv seal the rigid chimneys work the best .as for rings hone job round holes this is a big deal but if it was not doing it be for it should be still sealing up ?but you could of burnt down the side of a piston if so it will blow oil