Weather you have the old style alternator or the newer ones they both had only one field coil which energizes the alternator to make it put out current. The only difference is that the older alternators had one end of the field coil grounded internally and they regulated at the positive end of the field coil. The newer style alternators applied positive voltage to one side of the field winding and regulated the negative side using a solid state regulator. I suppose if you had a newer alternator and an old style regulator and you hooked it up to the positive field winding and grounded the other it would work for a while until or unless you exceed the current capability of the regulator in which case the regulator may fail. It all depends on how much current you need. If everything is stock you may be just fine with the older setup. If you have halogen lights, big boom box stereo etc, etc. you'll need more poop (that's a technical term) from your alternator so do the upgrade with the proper regulator.