And I ordered a Holley 94 1" aluminum carb spacer to put a fitting in for PCV conversion.  Does it matter what size the through hole is?  Ie. for affecting idle and vacuum or is that regulated by the PCV valve itself.  I am going to get original steel one for 60's era trucks 292 and drill and tap the block behind the valley pan.

Thanks guys.

The screw-in PCV set-up Dutchie put on here is a first class design and many have adopted it. But............the pipe threads on the usual Y-block truck service part are on the wrong end of the valve, the check valve is operating in the wrong direction. You'll need to find one with the proper orientation - or maybe someone here can give you a part number to do the job.

On my outfit - the Y-block part flowed way too much air into the carb base and made it the prime source of idle air (didn't work well) - so I orficed it to suit. Others have used a smaller PCV - but that would also present some challenges getting the right combination of threads for the block.

 
 Steve Metzger       Tucson, Arizona