Quill stems are measured by the total length, though they may list the maximum distance above the safety line. It's possible that an old Huffy used the old American stem size, not the current standard for a 1" threaded headset. You also need to check what size handlebar diameter you have and whether a new stem would fit that, or if you'd need new handlebars to match a new stem.
Oil is good, grease is better.
2007 Peter Mooney w/S&S couplers/Terry Butterfly
1993 Bridgestone MB-3/Avocet O2 Air 40W
1980 Columbus Frame with 1970 Campy parts
1954 Raleigh 3-speed/Brooks B72