Bottoming out a hydraulic lifter is not as easy as it sounds. I'ts done in racing and you need to know how your engine expansion (Head, Block) reacts when hot so you don't end up with an open valve. But for the quick purpose of checking the lifter
oil functioning capabilities I suppose it would work. With that being said, it ran quiet with the bottomed out lifter correct? No issues. In that case it really could be that you had two stuck lifters. If you had access to another Crane lifter I would try it like you wanted to do. Without being able to get another one, and after inspecting the cam lobe, lifter bore and rocker arm if all looks good I would order a set of Morels.