Dauntless Valve Covers...

On my 70 v6, the passenger side cover has the oil fill cap towards the front and the pcv valve towards the rear. On the driver side cover, there is the hole towards to the front for the air intake bypass (which would have originally had a hose connected from the air filter - oil bath in my case). I have a little breather in place of the hose for air intake bypass.

much like this (internet photo):


Here is the air bypass hose as it would have originally looked (with paper air filter):
https://cdn.barrett-jackson.com/staging/carlist/items/Fullsize/Cars/91711/91711_Engine_Web.JPG

 

Don't think its a huge issue...but the pcv system might not be quite as effecient. The pcv valve is the outlet of the system and returns the flow to the backside of the carb, and may not be able to flow much air through the crankcase if there is no direct air supplied through the 'bypass' inlet in the valve cover. Guessing it would affect emissions moreso than performance - and not all the critical anyway. Others on here know much more than I...

 

any FLAPS for about $5 or so... I think some have a slightly different diameter base tube/nipple that inserts into the valve cover grommet so just check to make sure its all the right fit. I replace mine every couple oil changes.