what's the extra hole in my GSL SE distributor cap for? Never noticed it until I lost the rubber plug on it and had starting problems after rinsing the engine compartment. It's now plugged with dumdum.

 

Looking at 12A dist caps over the years, they've all had vented covers over that hole. I assumed it was for letting out moist air buildup. Maybe pressure differential?

 

Sounds reasonable. I hope it doesn't need venting, because I've sealed the hole on mine

 

It lets the ozone out from all those sparks jumping under there.

 

Thanks!

 

It's just a vent. I would recommend getting another cap for the port instead of just sealing it.

 

Anyone have a vent from an old cap?

 

I drill extra holes in my caps, an old racer said that if you have an MSD it makes the terminals last a lot longer. Something about ozone buildup or something. It works, too.

Two 1/2" holes on the sides, below where the rotor spins.