Back in 2010 I replaced the dist cap & rotor. The thing is, there is a 3rd cap that sits in between the rotor and distrubutor (my finger's on it):





I've gotten two Bosch distributor kits from ipd since but they haven't included the small gray cap. My question is if I should reuse the cap a 2nd time or put it to the side?

 

Yea, keep using it. Some kind of dust cap or maybe 2nd protection against oil leakage if the cam seal starts leaking.

 

I left it out this time for now, it doesn't "clip" into the groove of the head, it just hangs and rests at a 45 degree angle between the cap and rotor.

I'll keep it just in case.

 

Once you screw the distributor cap on it sits where it should.

 

ok cool, thanks, i put it back in.

 

I would go with re-installing that "cone". I can't remember or find any info on it but I'm leaning toward it being a shield for oil that gets past the distributor shaft seal getting into the inside of the cap.