lol check this out.
 

http://johnsmustang.com/Parts/details-5700.html i know its in the wrong section but this is the only place that i feel at home...

now for my question what is this? http://johnsmustang.com/Catalog/2311/

It's either fake or something to suppress the annoying buzzing sound that comes through car stereo speakers in-sync with the engine RPM...seems to be very common on older cars I've had.

It's a noise suppressing capacitor and is used to smooth the voltage spikes in older charging systems.

The part is legit. It is simply a capacitor, sometimes called a condenser. These are placed in strategic places in the circuitry to filter out electrical interference and noise spikes. Based on the type of plug on it, I would say this one connects to the wiring harness at the voltage regulator. Old style distributors have them inside next to the points, but those have a different conector.

thanks! i will use this in conjunction with non resister spark plugs?

Ever handed a charged one to someone? If you touch both ends while it has a charge, talk about getting zapped. Seriously though dont play around with it, it HURTS!

On the old Mustangs you should be sure and use resistor wires if you don't use resistor plugs. Personally, I would use both to further reduce noise in the radio. The original AM radios were especially sensitive to plug wire noise. Using Neither will cause so much interferrence that the cars AROUND you will have poor reception on their AM stations!

If there is a specific "electrical noise" problem you have with your Mustang, PM me and we can take this off-line. I may have some ideas. As you said earlier, this isn't really the forum...

i know this isnt the forum i just found this interesting i was scrolling through the parts and i found this and ive never seen it before.