Replaced electrical system during restoration. New distributor cap, wires, coil, spark plugs. We do not have a spark so far and the coil is heating up almost too hot to touch. During purchase, was advised may require external resistor, we are unsure if we have one in our system or if one will be required. Also if one is required, what kind of resistor, and where to purchase would be our next question. Any help or advice on how to proceed to achieve a spark will be greatly appreciated. Thank you.