Will my alternator power my sub?

That low rated alternator is gonna burn out when you load it down with lights when the radio is on. Cars of that era aren't designed to support high power stereos ( back then, high power was below 50 watts). You may need a minimum of 75 amps to power all electrical loads on that battery, and a higher-rated battery ( 675 CCA or more). Don't you want high power from the engine?