I guess you are asking about positive ground or negative ground, a battery does not have reverse polarity it has a positive and negative pole. If it is a very early 430, made in the Rock Island plant then it will probably be positive ground unless somebody has reversed the polarity of your generator and converted it to negative ground system and then they would have had to switch the wires on the ammeter so it would read right and I doubt if a former owner would have gone to the trouble. If it was made after '62 I believe and in the Racine plant it will be negative ground or if it has been converted to an alternator it will be negative ground. You need to determine whether it is positve or negatve ground before you try to jump OR make sure you can see the POS/NEG molded into the tractor battery case and hook up your cables to the proper pole from battery to battery. Don't try to jump from the starter post and grounding on the tractor frame least you damage the system on the "donor" vehicle.