How leaky are new FE blocks?

[Silversmith]

Interesting Chas M8, but I have no pvc set up. My carb has mechanical secondaries, as does my distributor's advance. I have no need of a pvc valve. This old sideoiler runs top notch w/out one. It just blows oil. I presently have valve covers on with breather holes. As well as a set of covers (not used) that do not. The blow by seems to be comming from the oil filler cap/tube on the intake & dropping onto the inside rail of the valve cover & then driping down to create a fine mist that collects on the underside of the car. As for the breather cap on the passenger side (same as oil filler tube) it is connected to a hose that takes the excess oil down to a puke (part of accumulator system) tank located in the front of the roadster. The driver side breather is a standard Ford motorsport vented cap & that is where the oil drips onto the inside rail of the valve cover & does the same as the passenger side. My plan was to hook up the driver side to the passenger side via another hose & tie into the puke tank, using the same non vented style cap that is on the passenger side. Then extend the height of the oil (vented) filler cap to almost the same height as the turkey pan & see if that worked. The back intake breather tube that you modified does not leak oil on my engine. You say that there is only need for one vent required for the block? If that is so, then I might just install a non breather oil cap & do the hook up of both valve covers & see if that works? Any thoughts? By the way I just used standard cork gaskets from NAPA for the oil pan & valve cover gaskets & used your pan rail flattening advice & Rick's gasket installing advice & gave the sealers @ least 24 hrs to dry. The combo worked wicked good Man; when I refresh this old girls hart. I'm installing a set of quads like the photo's you showed

[ERA Chas]

Originally Posted by Silversmith

Interesting Chas M8, but I have no pvc set up. My carb has mechanical secondaries, as does my distributor's advance. I have no need of a pvc valve.

You're not understanding. If your baseplate has no fitting then find a safe spot on the intake just under the carb seat (generally at the rear of the carb) and drill and tap for one. Use my suggested parts and a short hose and you're done. You most certainly do need PCV. Do a leak down test and see percentage of combustion blowing past the rings and pressurizing the crank case.
I have no vac advance dizzy and carb secondary vac comes higher up above the baseplate.
All that open breather area is not doing what you need. At one time, I had four open breathers at once and still had mist and drips from pan to valve covers.
This is the fix I've needed all along.