Re: fitting a water pressure gauge
The factory telltales came out in the 78 model year. They drilled a hole in the exhaust cover to feed the telltale. Likely they created a boss (thicker part of the cover) in order to tap the new hole. I'd be inclined to buy a used bubbleback outer exhaust cover from a later model. Should bolt right in place. There have to be plenty of these used covers laying around in salvage yards.