Triple C,
The flasher is mounted on the inside driver's side of the cab above the brake pedal up to the left. Almost all mv uses the same one for a zillion years. They are easy to find at the major dealers. Since there is a slew of trucks for parts in the classifieds, there is a good chance you can get one reasonable there.
If you are going to convert to LED front or rear taillights, then you will need a solid state electronic flasher as the old mechanical or first generation does not flash the lights since they draw very little current. They are available at the dealers $70? and NAPA does sell the truck lite brand mv flasher but it is pricey $150?. If no leds in the future then the plain jane will work fine.
There is a thread in the electrical section about using a commercial 24v one and wiring it up but since they are easy to find, I don't recommend it.
Nice Truck and Welcome!
) I am in the KC area. Thanks in advance.