oil dye test

I own a 62 t-bird and its leaking somewhere. On the side of the block on the passenger side. I can put it on the car ramps but dont have a hydrulic lift. Would I be able to notice with what I have. Just a novice. How long does this stuff stay in the oil. Thanks Larry

Every leak dye I have ever used requires a black light to make it show up.
and it will stay there untill you change the oil.