Have recently converted my 312 engine to a Ford Autolite 4100-1.08 carb & a PCV setup. Used a later style rear vent valley cover for the valve location. It's not a fully closed system & the air intake is thru the oil filler cap. (clean & in good shape)  We've got the carb sorted so the idle is good. At idle the PCV seems to be working fine, virtually O crankcase smoke at the fill pipe. However, after driving it briefly, it's now blowing oil smoke when accelerated. I pulled the valve out & looked into the original oil deflector underneath & found noticeable oil residue there  So, first question is, am I using an incorrect PCV valve ?  The one I have is new but I had it on hand & don't recall what it was for originally. The # on it is 2072, USA made. I read somewhere that the valves need to be sized properly for the engine ?  Is that correct?  Thanks.   


Paul