I'm sending the OP copies of several Delco-Remy service manual pages. Also, there are numerous listings on Ebay for 6 volt cutout relays, at very reasonable prices. Other than normal engine compartment heat, a cutout relay should not get "warm". That probably indicates yours has some dirty points that are causing resistance in the charging circuit and developing some unwanted heat. I'd suggest either wiring the system according to the Delco diagrams with a new cutout, or simply acquiring a 6 volt golf cart battery and running on battery power alone for the one-time parade, using the generator with no wires attached as an idler for the water pump. A golf cart battery will have enough reserve capacity to run the engine for several hours with no charging system, unless a bunch of lights, sirens, etc. are also being operated at the same time.
Jerry

Edit: Also on Ebay, there are several 10-SI Delco alternators that have been converted to 6 Volt operation. They're in the $200.00 range, but that makes conversion to alternator charging more or less a "plug and play" situation with very little modification to the rest of the electrical system. No converting of lights, ignition, etc. to 12 volts.
Jerry

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