Bought a Van......

Good. On the other thread about the distributor, I meant to tell you that since you have the GM style HEI, it DOES NOT require a resistor of any kind. It gets straight 12V. Which may be to your advantage to check and MAKE SURE it is 12V because it won't run right unless it is.
Also, that black ugly box "computer" acts as the voltage regulator as well. Another one of it's star functions.