You say "I ordered a set of these from a Chrysler dealer some time back. But I don't recommend anyone doing that. The screws Chrysler substitutes are anodized steel and are 18 mm long rather than 16 mm. That extra 2 mm length gave me issues during re-assembly. I ended using marine grade steel bolts that have an anti-corrosion covering on them. Makes the screw compatible with the alloy valve covers"

Are you referring to the screws used on the valve covers or the breather vents atop the valve covers?

Thanks