The pulley size does make a difference as does the type of regulator they use and the air gap between the rotor and stator. You do typically get more amperage output from a two wire alternator as compared to a one wire at low engine rpms which is why most cars and trucks were built that way from the factory. Also one wire alternators have a constant internal electrical draw (about the same as a digital clock) so if you drive it every day or so life is good. If the truck sits in storage for a month or so you might have a dead battery unless you use a master switch or disconnect the battery (which are good ideas) But hey in your case if it is working...enjoy the ride. The trucks typically do not have a very high electrical load which also helps. I am just trying to help everyone understand the difference between the two types so when you shop for an alternator you know what you are buying.

Thanks Randy

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