The pictured Mickey Thompson valve covers have had the tubes added to accommodate crankcase breathers and or PCV valve cap although in the picture the tubes look larger than those on stock 1960s valve covers..
The 1960s Chrysler vehicles used a push-in style oil breather cap and/and or PCV valve cap or prior road draft tube and oil breather cap. The caps have a spring band to retain the cap in the tube when pressed into it.
The 1960 - 1966 (except some models with Cleaner Air Package (C.A.P.)) crankcase breather cap looks like the following image:
1966 models with C.A.P. and 1967 - 1969 model caps had a hose nipple to connect to the air cleaner like that shown in the following image:
The PCV valve and cap fits the same size tube and looks like the following image:
The stock tubes measure ~ 1/2 inch diameter as shown in the following images:
Aftermarket caps were available in different styles with two examples shown in the following image:
The tubes may be stuck in the valve cover openings due to age, but if they are the stock size, they can be used with stock style components of the era.
