When leak checking an engine be sure to lock the crankshaft but after the pressure is applied allow the engine rock or the crank to move very slightly. The top ring will not be seated on the bottom of the top ring land and the leaking will be around the back side of the ring. With just a slight movement of the piston, POP, the ring seats and you get your true leakage. I use 100 PSI,, and NO it will not seat that ring.
Example; an excellent prepared Briggs FH cylinder that leaks 1% or less will show about 13% under the above conditions. as soon as the ring touches the lower land, POP,, 1%.
Best, WP