Fuel Gauges

I am in the process of re-doing everything from stringers up in my 1969 Barracuda and was thinking about installing a gallons per hour gauge. I know that Shur-Flo makes a good product but was wondering if anyone had any experience with this type of setup.

Also I am looking to install these on my center console. It is equipped with twin 315hp Yanmar mechanical diesels. I have been told that you cannot install a flow gauge on these motors since the fuel going into the engine is not an accurate measurement due to the fact that there is a pressure side and a return side. I am relatively new to the world of diesels and would appreciate any input.