| That is the noise supressor for the radio, the voltage regulator should have one on it also ove on the drivers side of the firewall. The condesensor for the points would ahve been mounted inside the distributor next to the points. The other item you may or may not have by the coil is a larger condenseor/voltage reducer that drops the power to the coil to reduce burning up points.
With electronic ignition, I'm not sure on the reducer deal, I'm still running mine, instructions said to leave it.
As for this part, I would put it back on, can't hurt. It is supposed to absorb some of the stray static and pulse from the coil I beleive that would otherwise show up in your radio as a constant pounding hum that increases with RPM, more of an issue with the AM band than FM.
__________________ 1996 T100, Stock, nice truck
1973 FJ-40, Stock
1984 FJ-60, Stock, 225,000+miles 
2002 Subaru Forester L, for the wifey |