My 2004 Utopia's fuel and speedo have died. Not sure why, but they did. Tech at local repair shop said they are toast, but the sending units are fine. So, can I replace the 204470803 speedo with a 204470605 speedo? and the same for the fuel gauge, 204470804 with a 204470604. They look the same, but not sure if they will work. Any help is greatly appreciated. Cost difference is huge.