Water Heaters in '73? I had a '73 Excella 500. I just added a 120v outlet under the sink from the one over the sink. Then I plugged in the new Hot Rod after switching it with a 20amp single pole switch nearby the cabinet door.
The hot water heater on 120v ran a little cooler than the LP, but it was just fine and took about 1hour to recover. When traveling, it is cheaper to run on the CGs power than run your own LP. It is a good deal and pretty easy to install too.
Rich
wbcci3371@gmail.com