Finally gonna get it up and running
 

After the ultimate first-time engine work nightmare ( did a topend
for a dropped valve seat and got low compression in all 4 after reinstall)
my mechanic found the problem. The machine shop botched the
helicoil install on the heads (!). All 4 were loose and leaking. ( no loctite? Out
comes the motor for new helicoils and leakdown test, and if that's all right, on to jetting the carbs/curving the distributor.
Right now, I've got both head vaccum ports going into a bugpack breather box and the stock breather port ( on the oil filler breather) going into this as well. Is this
OK? I didn't like the idea of CV going into my carb air cleaners.

A spinning engine can develop a lot of pressure inside the crankcase (all engines have a small amount of blowby). The "breathers" you have on the head are to relieve this pressure to avoid blowing the front and rear main seals (and possibly others). You will note on the stock FI system, there is a hose from the oil filler (which has a baffle in it) to the air cleaner and some have hoses from the head to the air cleaner.

Venting to the atmosphere (to your bug pack breather) will suffice in relieving this pressure. Mount the breather high in the engine compartment.

Applying a small amount of vacuum to the system will ensure no pressure build up (attachment to the air filters). You shouldn't be blowing oil into the filters if your engine is built correctly.

Relief of the internal pressure can increase the HP of the engine ever so slightly. Drag racers used an induced vacuum system (one way valve welded into exhaust system = high speed gasses past an open port will induce a vacuum), however, it created a fire hazzard.

You might check out the SoptalkForums Type4rum for some good info. Here is a thread discussing venting.

http://shoptalkforums.com/bbs/NonCGI/Forum1/HTML/003534.html

Mike