every small cap distributor I have has had bad rust/corrosion of the pickup coil and reluctor because of ozone buildup while not a single "large cap"HEI of mine has ever had even a trace of this problem-so going to ventilate my "small caps"beyond just the two screened holes on the bottom:Thinking about adding a hole in cap with a vent pipe to air cleaner snorkel or air intake on back of alternator to keep ozone out.1992-93 "Optispark"dizzys had ozone damage problems including failed ball bearings,but 1994-up were ventilated.

 

You could try connecting to manifold vacuum with a very small diameter restriction (like .030" or less) in that line.

 

Or just route a hose to the intake duct work (like LTIs did) so you don't have a vac leak.