help with my uncles harley davidson

hey guys my uncle has a 1990 harley davidson FXSTC. he forgot the size of the gas tank for the gas stabilizor. anyone know were i could find this info or anyone know it?

It should be aprox. 3 gallons. It's not going to hurt if you use a little too much stabilizer. Just don't go overboard. Like I said, I would treat it as if it were a 3 gal. tank.