That's an awful lot of oil burning, if it's not leaking. A good way to differentiate between valves seals and piston rings is if after an oil change the oil darkens quickly, like within 500 miles. Oil getting sucked through bad valve seals doesn't darken the oil. Oil getting past the rings goes both ways, into the combustion chamber and back into the crankcase, loading the oil with combustion by-products and darkening the oil.

 

I tried that in past w/o success. better luck to you