Decided to pull my 460 packajet and 12JC pump this winter and rebuild them. I came accross this little electrical item that i cant identify. Is it some kind of fuse???

Also, any tips with rebuilding the engine would be appreciated as far as mild upgrades. It has never been rebuilt and has the original cast iron heads and cast iron SCJ manifold. The engine still runs very good and doesnt use any oil. Just getting a little tired. I want it to be reliable but wake it up a little bit. Maybe 375-400 horse. I think it was 320 originally.

Thanks for the advise!

ballast resistor? do you have the stock ignition?

Ballast resistor for the ignition coil circuit.

Yep Yep, If you look at the other side it has a resistor spring from one terminal to the other.