Is your truck converted to a 12 volt electrical system? If it's still 6 volt, you don't need a resistor. The resistor is used on a 12V system to drop the battery voltage to around 9 volts during normal running to prevent the points from burning. It's wired between the ignition switch and the coil (+) terminal, and it can be mounted anywhere on the firewall that's convenient, or even on the bracket that holds the coil onto the cylinder head. Putting it somewhere it can get airflow from the fan helps to keep it cool.
Jerry


"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!