I did seals on my 94 recently..drove it to colorado and back. (well over 2500 miles) it used less than a quart. sadly in my case I believe the rings are slightly worn due to running 10w30 for so long. (from about 115k to 177k .. it helped oil consumption greatly). When I had the air hose in each cylinder I could hear air escaping thru the timing cover..lol. Personally I found the annoying oil consumption well worth replacing the stem seals, but then again im used to doin stuff like this, and I still found the stem seals to be a b itch. Its a long job, and very tedious. you will need to find a good technique for reinstalling the keepers on the valve stem, I used a magnet and stuck one side on at a time time.. VERY tedious..lol.
"Responding to a question by saying do a search, look in a auto parts catalog, or call a mechanic isn't being helpful"

2003 Grand marquis all stock