It'll also probably blow the filter sock off the gas line in the tank. Personally, I think those things are useless and prefer a good external filter I can see and easily change. Those socks can get clogged over time.
69 RS Conv,355,M20,4.10's and I don't worry about stone chips ( yet ).
if I were to blow out the line, I would disconnect it at the rubber connector from the front/rear line to the tank sender line, by the passenger's side rear wheel, and also disconnect it at the pump. Then blow from back to front.